diff --git a/demo/Sandbox/App.axaml.cs b/demo/Sandbox/App.axaml.cs
index c6033ba..3ead0df 100644
--- a/demo/Sandbox/App.axaml.cs
+++ b/demo/Sandbox/App.axaml.cs
@@ -1,6 +1,5 @@
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
-using Avalonia.Data.Core;
 using Avalonia.Data.Core.Plugins;
 using Avalonia.Markup.Xaml;
 using Sandbox.ViewModels;
diff --git a/demo/Ursa.Demo.iOS/AppDelegate.cs b/demo/Ursa.Demo.iOS/AppDelegate.cs
index a565165..2954d1a 100644
--- a/demo/Ursa.Demo.iOS/AppDelegate.cs
+++ b/demo/Ursa.Demo.iOS/AppDelegate.cs
@@ -1,9 +1,6 @@
 using Foundation;
-using UIKit;
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.iOS;
-using Avalonia.Media;
 
 namespace Ursa.Demo.iOS;
 
diff --git a/demo/Ursa.Demo/Converters/IconNameConverter.cs b/demo/Ursa.Demo/Converters/IconNameConverter.cs
index 4d1fe99..98c82c6 100644
--- a/demo/Ursa.Demo/Converters/IconNameConverter.cs
+++ b/demo/Ursa.Demo/Converters/IconNameConverter.cs
@@ -1,9 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using Avalonia;
-using Avalonia.Controls.Shapes;
 using Avalonia.Data.Converters;
 using Avalonia.Media;
 using Avalonia.Metadata;
@@ -25,7 +23,7 @@ public class IconNameConverter: IValueConverter
         return AvaloniaProperty.UnsetValue;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/demo/Ursa.Demo/Converters/IconNameToPathConverter.cs b/demo/Ursa.Demo/Converters/IconNameToPathConverter.cs
index 4451895..d9e2a08 100644
--- a/demo/Ursa.Demo/Converters/IconNameToPathConverter.cs
+++ b/demo/Ursa.Demo/Converters/IconNameToPathConverter.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Globalization;
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Data.Converters;
 using Avalonia.Media;
 
@@ -9,7 +8,7 @@ namespace Ursa.Demo.Converters;
 
 public class IconNameToPathConverter: IValueConverter
 {
-    private string[] paths = new[]
+    private readonly string[] _paths = new[]
     {
         "M12,4A4,4 0 0,1 16,8A4,4 0 0,1 12,12A4,4 0 0,1 8,8A4,4 0 0,1 12,4M12,14C16.42,14 20,15.79 20,18V20H4V18C4,15.79 7.58,14 12,14Z",
         "M16 12L9 2L2 12H3.86L0 18H7V22H11V18H18L14.14 12H16M20.14 12H22L15 2L12.61 5.41L17.92 13H15.97L19.19 18H24L20.14 12M13 19H17V22H13V19Z",
@@ -19,23 +18,23 @@ public class IconNameToPathConverter: IValueConverter
         "M16.67,4H15V2H9V4H7.33A1.33,1.33 0 0,0 6,5.33V20.67C6,21.4 6.6,22 7.33,22H16.67A1.33,1.33 0 0,0 18,20.67V5.33C18,4.6 17.4,4 16.67,4Z",
         "M12 2C6.5 2 2 6.5 2 12C2 17.5 6.5 22 12 22C17.5 22 22 17.5 22 12S17.5 2 12 2M12.5 13H11V7H12.5V11.3L16.2 9.2L17 10.5L12.5 13Z"
     };
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is int i)
         {
-            string s = paths[i % paths.Length];
+            var s = _paths[i % _paths.Length];
             return StreamGeometry.Parse(s);
         }
         else if (value is string s)
         {
-            int hash = s.GetHashCode();
-            string path = paths[Math.Abs(hash) % paths.Length];
+            var hash = s.GetHashCode();
+            var path = _paths[Math.Abs(hash) % _paths.Length];
             return StreamGeometry.Parse(path);
         }
-        return AvaloniaProperty.UnsetValue;
+        return AvaloniaProperty.UnsetValue; 
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         return AvaloniaProperty.UnsetValue;
     }
diff --git a/demo/Ursa.Demo/Converters/TimelineIconConverter.cs b/demo/Ursa.Demo/Converters/TimelineIconConverter.cs
index 04d46f4..8197a63 100644
--- a/demo/Ursa.Demo/Converters/TimelineIconConverter.cs
+++ b/demo/Ursa.Demo/Converters/TimelineIconConverter.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Globalization;
 using Avalonia;
-using Avalonia.Data;
 using Avalonia.Data.Converters;
 using Avalonia.Media;
 using Ursa.Controls;
@@ -10,7 +9,7 @@ namespace Ursa.Demo.Converters;
 
 public class TimelineIconConverter: IValueConverter
 {
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is TimelineItemType t)
         {
@@ -25,7 +24,7 @@ public class TimelineIconConverter: IValueConverter
         return AvaloniaProperty.UnsetValue;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/demo/Ursa.Demo/DataTemplates/ToolBarItemTemplateSelector.cs b/demo/Ursa.Demo/DataTemplates/ToolBarItemTemplateSelector.cs
index bfd9c76..fcbe6a4 100644
--- a/demo/Ursa.Demo/DataTemplates/ToolBarItemTemplateSelector.cs
+++ b/demo/Ursa.Demo/DataTemplates/ToolBarItemTemplateSelector.cs
@@ -14,11 +14,11 @@ public class ToolBarItemTemplateSelector: IDataTemplate
     public Control? Build(object? param)
     {
         if (param is null) return null;
-        if (param is ToolBarSeparatorViewModel sep)
+        if (param is ToolBarSeparatorViewModel)
         {
             return new ToolBarSeparator();
         }
-        if (param is ToolBarButtonItemViewModel vm)
+        if (param is ToolBarButtonItemViewModel)
         {
             return new Button()
             {
@@ -27,7 +27,7 @@ public class ToolBarItemTemplateSelector: IDataTemplate
                 [!ToolBar.OverflowModeProperty] = new Binding(){Path = nameof(ToolBarItemViewModel.OverflowMode)},
             };
         }
-        if (param is ToolBarCheckBoxItemViweModel cb)
+        if (param is ToolBarCheckBoxItemViweModel)
         {
             return new CheckBox()
             {
@@ -36,7 +36,7 @@ public class ToolBarItemTemplateSelector: IDataTemplate
                 [!ToolBar.OverflowModeProperty] = new Binding(){Path = nameof(ToolBarItemViewModel.OverflowMode)},
             };
         }
-        if (param is ToolBarComboBoxItemViewModel combo)
+        if (param is ToolBarComboBoxItemViewModel)
         {
             return new ComboBox()
             {
diff --git a/demo/Ursa.Demo/DataTemplates/ViewLocator.cs b/demo/Ursa.Demo/DataTemplates/ViewLocator.cs
index fbbbece..15e3d99 100644
--- a/demo/Ursa.Demo/DataTemplates/ViewLocator.cs
+++ b/demo/Ursa.Demo/DataTemplates/ViewLocator.cs
@@ -1,7 +1,6 @@
 using System;
 using Avalonia.Controls;
 using Avalonia.Controls.Templates;
-using Ursa.Demo.Pages;
 
 namespace Ursa.Demo.Converters;
 
@@ -10,16 +9,13 @@ public class ViewLocator: IDataTemplate
     public Control? Build(object? param)
     {
         if (param is null) return null;
-        var name = param.GetType().Name!.Replace("ViewModel", "");
+        var name = param.GetType().Name.Replace("ViewModel", "");
         var type = Type.GetType("Ursa.Demo.Pages."+name);
         if (type != null)
         {
             return (Control)Activator.CreateInstance(type)!;
         }
-        else
-        {
-            return new TextBlock { Text = "Not Found: " + name };
-        }
+        return new TextBlock { Text = "Not Found: " + name };
     }
 
     public bool Match(object? data)
diff --git a/demo/Ursa.Demo/Dialogs/DialogWithAction.axaml.cs b/demo/Ursa.Demo/Dialogs/DialogWithAction.axaml.cs
index 783f47b..08724f8 100644
--- a/demo/Ursa.Demo/Dialogs/DialogWithAction.axaml.cs
+++ b/demo/Ursa.Demo/Dialogs/DialogWithAction.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Dialogs;
 
diff --git a/demo/Ursa.Demo/Dialogs/PlainDialog.axaml.cs b/demo/Ursa.Demo/Dialogs/PlainDialog.axaml.cs
index 1e4be06..4110bb6 100644
--- a/demo/Ursa.Demo/Dialogs/PlainDialog.axaml.cs
+++ b/demo/Ursa.Demo/Dialogs/PlainDialog.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Dialogs;
 
diff --git a/demo/Ursa.Demo/Pages/AvatarDemo.axaml.cs b/demo/Ursa.Demo/Pages/AvatarDemo.axaml.cs
index 5bc2485..cffff7d 100644
--- a/demo/Ursa.Demo/Pages/AvatarDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/AvatarDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/BadgeDemo.axaml.cs b/demo/Ursa.Demo/Pages/BadgeDemo.axaml.cs
index eec79bf..7caa06c 100644
--- a/demo/Ursa.Demo/Pages/BadgeDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/BadgeDemo.axaml.cs
@@ -1,4 +1,3 @@
-using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
diff --git a/demo/Ursa.Demo/Pages/BannerDemo.axaml.cs b/demo/Ursa.Demo/Pages/BannerDemo.axaml.cs
index 72a772d..cd7b94d 100644
--- a/demo/Ursa.Demo/Pages/BannerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/BannerDemo.axaml.cs
@@ -1,5 +1,4 @@
 using System.Collections.ObjectModel;
-using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Notifications;
 using Avalonia.Markup.Xaml;
@@ -23,9 +22,9 @@ public partial class BannerDemo : UserControl
 
 public class BannerDemoViewModel : ViewModelBase
 {
-    private ObservableCollection<NotificationType> _types;
+    private ObservableCollection<NotificationType>? _types;
 
-    public ObservableCollection<NotificationType> Types
+    public ObservableCollection<NotificationType>? Types
     {
         get => _types;
         set => SetProperty(ref _types, value);
diff --git a/demo/Ursa.Demo/Pages/BreadcrumbDemo.axaml.cs b/demo/Ursa.Demo/Pages/BreadcrumbDemo.axaml.cs
index c119fc7..1f63393 100644
--- a/demo/Ursa.Demo/Pages/BreadcrumbDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/BreadcrumbDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/ButtonGroupDemo.axaml.cs b/demo/Ursa.Demo/Pages/ButtonGroupDemo.axaml.cs
index 533130a..5b00129 100644
--- a/demo/Ursa.Demo/Pages/ButtonGroupDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/ButtonGroupDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 using Ursa.Demo.ViewModels;
 
 namespace Ursa.Demo.Pages;
@@ -10,6 +8,6 @@ public partial class ButtonGroupDemo : UserControl
     public ButtonGroupDemo()
     {
         InitializeComponent();
-        this.DataContext = new ButtonGroupDemoViewModel();
+        DataContext = new ButtonGroupDemoViewModel();
     }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/Pages/ClassInputDemo.axaml.cs b/demo/Ursa.Demo/Pages/ClassInputDemo.axaml.cs
index 30e502a..851cb7b 100644
--- a/demo/Ursa.Demo/Pages/ClassInputDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/ClassInputDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/ClockDemo.axaml.cs b/demo/Ursa.Demo/Pages/ClockDemo.axaml.cs
index 058136a..3db30dd 100644
--- a/demo/Ursa.Demo/Pages/ClockDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/ClockDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/DatePickerDemo.axaml.cs b/demo/Ursa.Demo/Pages/DatePickerDemo.axaml.cs
index e38d30d..74214c7 100644
--- a/demo/Ursa.Demo/Pages/DatePickerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/DatePickerDemo.axaml.cs
@@ -1,7 +1,5 @@
 using System.Diagnostics;
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 using Ursa.Controls;
 
 namespace Ursa.Demo.Pages;
@@ -13,12 +11,12 @@ public partial class DatePickerDemo : UserControl
         InitializeComponent();
     }
 
-    private void CalendarView_OnOnDateSelected(object? sender, CalendarDayButtonEventArgs e)
+    private void CalendarView_OnOnDateSelected(object? _, CalendarDayButtonEventArgs e)
     {
         Debug.WriteLine("Pressed: "+ e.Date?.ToLongDateString());
     }
 
-    private void CalendarView_OnOnDatePreviewed(object? sender, CalendarDayButtonEventArgs e)
+    private void CalendarView_OnOnDatePreviewed(object? _, CalendarDayButtonEventArgs e)
     {
         Debug.WriteLine("Hovered: "+e.Date?.ToLongDateString());
     }
diff --git a/demo/Ursa.Demo/Pages/DialogDemo.axaml.cs b/demo/Ursa.Demo/Pages/DialogDemo.axaml.cs
index 2453f1a..ed838eb 100644
--- a/demo/Ursa.Demo/Pages/DialogDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/DialogDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/DisableContainerDemo.axaml.cs b/demo/Ursa.Demo/Pages/DisableContainerDemo.axaml.cs
index 68b6fbd..0476b6c 100644
--- a/demo/Ursa.Demo/Pages/DisableContainerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/DisableContainerDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/DividerDemo.axaml.cs b/demo/Ursa.Demo/Pages/DividerDemo.axaml.cs
index bdd3bd4..9f3018a 100644
--- a/demo/Ursa.Demo/Pages/DividerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/DividerDemo.axaml.cs
@@ -1,4 +1,3 @@
-using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
diff --git a/demo/Ursa.Demo/Pages/DrawerDemo.axaml b/demo/Ursa.Demo/Pages/DrawerDemo.axaml
index 2429a65..96b1eac 100644
--- a/demo/Ursa.Demo/Pages/DrawerDemo.axaml
+++ b/demo/Ursa.Demo/Pages/DrawerDemo.axaml
@@ -2,7 +2,6 @@
     x:Class="Ursa.Demo.Pages.DrawerDemo"
     xmlns="https://github.com/avaloniaui"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:common="clr-namespace:Ursa.Common;assembly=Ursa"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     xmlns:u="https://irihi.tech/ursa"
diff --git a/demo/Ursa.Demo/Pages/DrawerDemo.axaml.cs b/demo/Ursa.Demo/Pages/DrawerDemo.axaml.cs
index 3aa8916..788fa0d 100644
--- a/demo/Ursa.Demo/Pages/DrawerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/DrawerDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/EnumSelectorDemo.axaml.cs b/demo/Ursa.Demo/Pages/EnumSelectorDemo.axaml.cs
index da6250a..a1bbd81 100644
--- a/demo/Ursa.Demo/Pages/EnumSelectorDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/EnumSelectorDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/FormDemo.axaml.cs b/demo/Ursa.Demo/Pages/FormDemo.axaml.cs
index 64a5f0c..3881d9b 100644
--- a/demo/Ursa.Demo/Pages/FormDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/FormDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/IPv4BoxDemo.axaml.cs b/demo/Ursa.Demo/Pages/IPv4BoxDemo.axaml.cs
index c3a050c..fc8b272 100644
--- a/demo/Ursa.Demo/Pages/IPv4BoxDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/IPv4BoxDemo.axaml.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Net;
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
-using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/IconButtonDemo.axaml.cs b/demo/Ursa.Demo/Pages/IconButtonDemo.axaml.cs
index 4b2931d..bb07fc8 100644
--- a/demo/Ursa.Demo/Pages/IconButtonDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/IconButtonDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/ImageViewerDemo.axaml.cs b/demo/Ursa.Demo/Pages/ImageViewerDemo.axaml.cs
index 7aa908c..e558339 100644
--- a/demo/Ursa.Demo/Pages/ImageViewerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/ImageViewerDemo.axaml.cs
@@ -1,7 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Interactivity;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/IntroductionDemo.axaml b/demo/Ursa.Demo/Pages/IntroductionDemo.axaml
index ba2bbbf..c292152 100644
--- a/demo/Ursa.Demo/Pages/IntroductionDemo.axaml
+++ b/demo/Ursa.Demo/Pages/IntroductionDemo.axaml
@@ -2,7 +2,6 @@
     x:Class="Ursa.Demo.Pages.IntroductionDemo"
     xmlns="https://github.com/avaloniaui"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:converters="clr-namespace:Ursa.Demo.Converters"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     xmlns:u="https://irihi.tech/ursa"
diff --git a/demo/Ursa.Demo/Pages/IntroductionDemo.axaml.cs b/demo/Ursa.Demo/Pages/IntroductionDemo.axaml.cs
index ec1ee5c..2dab9c9 100644
--- a/demo/Ursa.Demo/Pages/IntroductionDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/IntroductionDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/KeyGestureInputDemo.axaml.cs b/demo/Ursa.Demo/Pages/KeyGestureInputDemo.axaml.cs
index f213756..c5fc35f 100644
--- a/demo/Ursa.Demo/Pages/KeyGestureInputDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/KeyGestureInputDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
@@ -10,9 +8,4 @@ public partial class KeyGestureInputDemo : UserControl
     {
         InitializeComponent();
     }
-
-    private void InitializeComponent()
-    {
-        AvaloniaXamlLoader.Load(this);
-    }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/Pages/LoadingDemo.axaml.cs b/demo/Ursa.Demo/Pages/LoadingDemo.axaml.cs
index cfbc0e8..65a17f2 100644
--- a/demo/Ursa.Demo/Pages/LoadingDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/LoadingDemo.axaml.cs
@@ -1,4 +1,3 @@
-using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
diff --git a/demo/Ursa.Demo/Pages/MessageBoxDemo.axaml.cs b/demo/Ursa.Demo/Pages/MessageBoxDemo.axaml.cs
index 0b5cf40..cfdc4c9 100644
--- a/demo/Ursa.Demo/Pages/MessageBoxDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/MessageBoxDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 using Ursa.Demo.ViewModels;
 
 namespace Ursa.Demo.Pages;
diff --git a/demo/Ursa.Demo/Pages/MultiComboBoxDemo.axaml.cs b/demo/Ursa.Demo/Pages/MultiComboBoxDemo.axaml.cs
index 2a51be5..9c67a7f 100644
--- a/demo/Ursa.Demo/Pages/MultiComboBoxDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/MultiComboBoxDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/NavMenuDemo.axaml.cs b/demo/Ursa.Demo/Pages/NavMenuDemo.axaml.cs
index eac27af..d1bae7d 100644
--- a/demo/Ursa.Demo/Pages/NavMenuDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/NavMenuDemo.axaml.cs
@@ -1,9 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Controls.Shapes;
-using Avalonia.Input;
-using Avalonia.LogicalTree;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 using Ursa.Demo.ViewModels;
 
 namespace Ursa.Demo.Pages;
@@ -13,15 +8,6 @@ public partial class NavMenuDemo : UserControl
     public NavMenuDemo()
     {
         InitializeComponent();
-        this.DataContext = new NavMenuDemoViewModel();
-    }
-
-    private void InputElement_OnPointerPressed(object? sender, PointerPressedEventArgs e)
-    {
-        if (sender is Rectangle c)
-        {
-            c.ApplyStyling();
-            var ancestors = c.GetLogicalAncestors();
-        }
+        DataContext = new NavMenuDemoViewModel();
     }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/Pages/NumPadDemo.axaml.cs b/demo/Ursa.Demo/Pages/NumPadDemo.axaml.cs
index b82a6ae..8e3a09e 100644
--- a/demo/Ursa.Demo/Pages/NumPadDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/NumPadDemo.axaml.cs
@@ -1,7 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Input;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/NumberDisplayerDemo.axaml.cs b/demo/Ursa.Demo/Pages/NumberDisplayerDemo.axaml.cs
index 35df3ef..ea47763 100644
--- a/demo/Ursa.Demo/Pages/NumberDisplayerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/NumberDisplayerDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml b/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml
index 75baa53..610c37a 100644
--- a/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml
+++ b/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml
@@ -55,7 +55,7 @@
             Grid.Row="1"
             Grid.Column="0"
             HorizontalAlignment="Left">
-            <StackPanel Grid.Row="1">
+            <StackPanel>
                 <u:Divider Content="{Binding #input.Value, StringFormat='Int = {0}'}" />
                 <u:NumericIntUpDown
                     Name="input"
@@ -148,9 +148,9 @@
             <CheckBox Content="IsReadOnly" IsChecked="{Binding IsReadOnly}" />
 
             <Label Content="HorizontalAlignment" />
-            <ComboBox ItemsSource="{Binding Array_HorizontalAlignment}" SelectedItem="{Binding HorizontalAlignment}" />
+            <ComboBox ItemsSource="{Binding ArrayHorizontalAlignment}" SelectedItem="{Binding HorizontalAlignment}" />
             <Label Content="HorizontalContentAlignment" />
-            <ComboBox ItemsSource="{Binding Array_HorizontalContentAlignment}" SelectedItem="{Binding HorizontalContentAlignment}" />
+            <ComboBox ItemsSource="{Binding ArrayHorizontalContentAlignment}" SelectedItem="{Binding HorizontalContentAlignment}" />
 
             <TextBox
                 InnerLeftContent="InnerLeftContent"
@@ -166,7 +166,7 @@
                 Text="{Binding FormatString}" />
 
             <Label Content="ParsingNumberStyle" />
-            <ComboBox ItemsSource="{Binding Array_ParsingNumberStyle}" SelectedItem="{Binding ParsingNumberStyle}" />
+            <ComboBox ItemsSource="{Binding ArrayParsingNumberStyle}" SelectedItem="{Binding ParsingNumberStyle}" />
 
             <CheckBox Content="AllowSpin" IsChecked="{Binding AllowSpin}" />
 
diff --git a/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml.cs b/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml.cs
index 8ca1387..40e00de 100644
--- a/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/NumericUpDownDemo.axaml.cs
@@ -1,7 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
-using System;
+using Avalonia.Controls;
 using System.Diagnostics;
 using Ursa.Controls;
 using Ursa.Demo.ViewModels;
@@ -19,7 +16,9 @@ public partial class NumericUpDownDemo : UserControl
 
     private void Numd_ValueChanged(object? sender, ValueChangedEventArgs<uint> e)
     {
-        Trace.WriteLine($"{(sender as NumericUIntUpDown).Name} {e.OldValue} {e.NewValue}");
-
+        if (sender is NumericIntUpDown i)
+        {
+            Trace.WriteLine($"{i.Name} {e.OldValue} {e.NewValue}");
+        }
     }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/Pages/PaginationDemo.axaml.cs b/demo/Ursa.Demo/Pages/PaginationDemo.axaml.cs
index 3418732..0377132 100644
--- a/demo/Ursa.Demo/Pages/PaginationDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/PaginationDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 using Ursa.Demo.ViewModels;
 
 namespace Ursa.Demo.Pages;
diff --git a/demo/Ursa.Demo/Pages/RangeSliderDemo.axaml.cs b/demo/Ursa.Demo/Pages/RangeSliderDemo.axaml.cs
index fe3181d..920b149 100644
--- a/demo/Ursa.Demo/Pages/RangeSliderDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/RangeSliderDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 using Ursa.Demo.ViewModels;
 
 namespace Ursa.Demo.Pages;
diff --git a/demo/Ursa.Demo/Pages/ScrollToButtonDemo.axaml.cs b/demo/Ursa.Demo/Pages/ScrollToButtonDemo.axaml.cs
index 5e7741c..1c57352 100644
--- a/demo/Ursa.Demo/Pages/ScrollToButtonDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/ScrollToButtonDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/SelectionBoxDemo.axaml.cs b/demo/Ursa.Demo/Pages/SelectionBoxDemo.axaml.cs
index 60d5ccd..23ec21e 100644
--- a/demo/Ursa.Demo/Pages/SelectionBoxDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/SelectionBoxDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/TagInputDemo.axaml.cs b/demo/Ursa.Demo/Pages/TagInputDemo.axaml.cs
index f19dc0a..1a72bcd 100644
--- a/demo/Ursa.Demo/Pages/TagInputDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/TagInputDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/ThemeTogglerDemo.axaml.cs b/demo/Ursa.Demo/Pages/ThemeTogglerDemo.axaml.cs
index a8e48c6..85cabf1 100644
--- a/demo/Ursa.Demo/Pages/ThemeTogglerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/ThemeTogglerDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/TimeBoxDemo.axaml.cs b/demo/Ursa.Demo/Pages/TimeBoxDemo.axaml.cs
index 5811b1b..d5072b0 100644
--- a/demo/Ursa.Demo/Pages/TimeBoxDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/TimeBoxDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/TimePickerDemo.axaml.cs b/demo/Ursa.Demo/Pages/TimePickerDemo.axaml.cs
index 330eb98..182be59 100644
--- a/demo/Ursa.Demo/Pages/TimePickerDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/TimePickerDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/TimelineDemo.axaml.cs b/demo/Ursa.Demo/Pages/TimelineDemo.axaml.cs
index fe07b76..a8f4819 100644
--- a/demo/Ursa.Demo/Pages/TimelineDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/TimelineDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 using Ursa.Demo.ViewModels;
 
 namespace Ursa.Demo.Pages;
diff --git a/demo/Ursa.Demo/Pages/ToolBarDemo.axaml.cs b/demo/Ursa.Demo/Pages/ToolBarDemo.axaml.cs
index f9f0f8f..0fd3ee4 100644
--- a/demo/Ursa.Demo/Pages/ToolBarDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/ToolBarDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/TreeComboBoxDemo.axaml.cs b/demo/Ursa.Demo/Pages/TreeComboBoxDemo.axaml.cs
index 6338466..6a6bc05 100644
--- a/demo/Ursa.Demo/Pages/TreeComboBoxDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/TreeComboBoxDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/TwoTonePathIconDemo.axaml.cs b/demo/Ursa.Demo/Pages/TwoTonePathIconDemo.axaml.cs
index 72e0a25..c042fb4 100644
--- a/demo/Ursa.Demo/Pages/TwoTonePathIconDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/TwoTonePathIconDemo.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.Demo.Pages;
 
diff --git a/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml b/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml
index 43e4ac8..77c7cd6 100644
--- a/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml
+++ b/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml
@@ -4,7 +4,6 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:u="https://irihi.tech/ursa"
              xmlns:vm="using:Ursa.Demo.ViewModels"
-             xmlns:system="clr-namespace:System;assembly=System.Runtime"
              x:DataType="vm:VerificationCodeDemoViewModel"
              x:CompileBindings="True"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
diff --git a/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml.cs b/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml.cs
index 5933b5c..23f9bb0 100644
--- a/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml.cs
+++ b/demo/Ursa.Demo/Pages/VerificationCodeDemo.axaml.cs
@@ -1,7 +1,4 @@
-using System;
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 using Ursa.Controls;
 
 namespace Ursa.Demo.Pages;
@@ -13,7 +10,7 @@ public partial class VerificationCodeDemo : UserControl
         InitializeComponent();
     }
 
-    private async void VerificationCode_OnComplete(object? sender, VerificationCodeCompleteEventArgs e)
+    private async void VerificationCode_OnComplete(object? _, VerificationCodeCompleteEventArgs e)
     {
         var text = string.Join(string.Empty, e.Code);
         await MessageBox.ShowOverlayAsync(text);
diff --git a/demo/Ursa.Demo/ViewModels/BreadcrumbDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/BreadcrumbDemoViewModel.cs
index d5dbbee..1e696b4 100644
--- a/demo/Ursa.Demo/ViewModels/BreadcrumbDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/BreadcrumbDemoViewModel.cs
@@ -8,34 +8,29 @@ namespace Ursa.Demo.ViewModels;
 
 public class BreadcrumbDemoViewModel: ObservableObject
 {
-    public ObservableCollection<BreadcrumbDemoItem> Items1 { get; set; }
-
-    public BreadcrumbDemoViewModel()
-    {
-        Items1 = new ObservableCollection<BreadcrumbDemoItem>()
-        {
-            new BreadcrumbDemoItem() { Section = "Home", Icon = "Home" },
-            new BreadcrumbDemoItem() { Section = "Page 1", Icon = "Page" },
-            new BreadcrumbDemoItem() { Section = "Page 2", Icon = "Page" },
-            new BreadcrumbDemoItem() { Section = "Page 3", Icon = "Page" },
-            new BreadcrumbDemoItem() { Section = "Page 4", Icon = "Page", IsReadOnly = true},
-        };
-    }
+    public ObservableCollection<BreadcrumbDemoItem> Items1 { get; set; } =
+    [
+        new BreadcrumbDemoItem { Section = "Home", Icon = "Home" },
+        new BreadcrumbDemoItem { Section = "Page 1", Icon = "Page" },
+        new BreadcrumbDemoItem { Section = "Page 2", Icon = "Page" },
+        new BreadcrumbDemoItem { Section = "Page 3", Icon = "Page" },
+        new BreadcrumbDemoItem { Section = "Page 4", Icon = "Page", IsReadOnly = true }
+    ];
 }
 
 public partial class BreadcrumbDemoItem: ObservableObject
 {
-    public string Section { get; set; }
-    public string Icon { get; set; }
+    public string? Section { get; set; }
+    public string? Icon { get; set; }
     [ObservableProperty] private bool _isReadOnly;
     
     public ICommand Command { get; set; }
 
     public BreadcrumbDemoItem()
     {
-        Command = new RelayCommand(() =>
+        Command = new AsyncRelayCommand(async () =>
         {
-            MessageBox.ShowOverlayAsync(Section);
+            await MessageBox.ShowOverlayAsync(Section ?? string.Empty);
         });
     }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/ViewModels/DialogDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/DialogDemoViewModel.cs
index 46e6c86..d966e9f 100644
--- a/demo/Ursa.Demo/ViewModels/DialogDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/DialogDemoViewModel.cs
@@ -4,10 +4,8 @@ using System.Threading.Tasks;
 using System.Windows.Input;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
-using Ursa.Common;
 using Ursa.Controls;
 using Ursa.Demo.Dialogs;
-using Ursa.Demo.Pages;
 
 namespace Ursa.Demo.ViewModels;
 
diff --git a/demo/Ursa.Demo/ViewModels/EnumSelectorDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/EnumSelectorDemoViewModel.cs
index 06be6d4..5877b24 100644
--- a/demo/Ursa.Demo/ViewModels/EnumSelectorDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/EnumSelectorDemoViewModel.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Collections.ObjectModel;
 using System.ComponentModel;
-using System.Windows.Input;
 using Avalonia.Animation;
 using Avalonia.Controls;
 using Avalonia.Data;
@@ -9,7 +8,6 @@ using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Layout;
 using CommunityToolkit.Mvvm.ComponentModel;
-using CommunityToolkit.Mvvm.Input;
 
 namespace Ursa.Demo.ViewModels;
 
diff --git a/demo/Ursa.Demo/ViewModels/FormDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/FormDemoViewModel.cs
index 4f2d459..9ef65ed 100644
--- a/demo/Ursa.Demo/ViewModels/FormDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/FormDemoViewModel.cs
@@ -37,7 +37,7 @@ public partial class FormDemoViewModel : ObservableObject
 
 public partial class DataModel : ObservableObject
 {
-    private string _name;
+    private string _name = string.Empty;
 
     [MinLength(10)]
     public string Name
@@ -55,7 +55,7 @@ public partial class DataModel : ObservableObject
         set => SetProperty(ref _number, value);
     }
 
-    private string _email;
+    private string _email = string.Empty;
 
     [EmailAddress]
     public string Email
diff --git a/demo/Ursa.Demo/ViewModels/MainViewViewModel.cs b/demo/Ursa.Demo/ViewModels/MainViewViewModel.cs
index 4bd2bab..6d34758 100644
--- a/demo/Ursa.Demo/ViewModels/MainViewViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/MainViewViewModel.cs
@@ -1,4 +1,5 @@
-using CommunityToolkit.Mvvm.Messaging;
+using System;
+using CommunityToolkit.Mvvm.Messaging;
 
 namespace Ursa.Demo.ViewModels;
 
@@ -67,6 +68,7 @@ public class MainViewViewModel : ViewModelBase
             MenuKeys.MenuKeyToolBar => new ToolBarDemoViewModel(),
             MenuKeys.MenuKeyTimeBox => new TimeBoxDemoViewModel(),
             MenuKeys.MenuKeyVerificationCode => new VerificationCodeDemoViewModel(),
+            _ => throw new ArgumentOutOfRangeException(nameof(s), s, null)
         };
     }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/ViewModels/MenuItemViewModel.cs b/demo/Ursa.Demo/ViewModels/MenuItemViewModel.cs
index 279fb52..04aa4d9 100644
--- a/demo/Ursa.Demo/ViewModels/MenuItemViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/MenuItemViewModel.cs
@@ -14,10 +14,10 @@ public enum ControlStatus
 
 public class MenuItemViewModel: ViewModelBase
 {
-    public string MenuHeader { get; set; }
-    public string MenuIconName { get; set; }
-    public string Key { get; set; }
-    public string Status { get; set; }
+    public string? MenuHeader { get; set; }
+    public string? MenuIconName { get; set; }
+    public string? Key { get; set; }
+    public string? Status { get; set; }
     
     public bool IsSeparator { get; set; }
     public ObservableCollection<MenuItemViewModel> Children { get; set; } = new();
@@ -31,7 +31,7 @@ public class MenuItemViewModel: ViewModelBase
 
     private void OnActivate()
     {
-        if (IsSeparator) return;
-        WeakReferenceMessenger.Default.Send<string>(Key);
+        if (IsSeparator || Key is null) return;
+        WeakReferenceMessenger.Default.Send(Key);
     }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/ViewModels/MessageBoxDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/MessageBoxDemoViewModel.cs
index e3a6d5c..a835796 100644
--- a/demo/Ursa.Demo/ViewModels/MessageBoxDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/MessageBoxDemoViewModel.cs
@@ -14,7 +14,7 @@ public class MessageBoxDemoViewModel: ObservableObject
 
     private readonly string _shortMessage = "Welcome to Ursa Avalonia!";
     private string _message;
-    private string _title;
+    private string? _title;
 
     public ICommand DefaultMessageBoxCommand { get; set; }
     public ICommand OkCommand { get; set; }
diff --git a/demo/Ursa.Demo/ViewModels/NumericUpDownDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/NumericUpDownDemoViewModel.cs
index 663b5f1..a4f4435 100644
--- a/demo/Ursa.Demo/ViewModels/NumericUpDownDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/NumericUpDownDemoViewModel.cs
@@ -1,11 +1,8 @@
-using Avalonia.Controls;
-using Avalonia.Layout;
+using Avalonia.Layout;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using System;
 using System.Globalization;
-using Ursa.Controls;
-using static System.Runtime.InteropServices.JavaScript.JSType;
 
 namespace Ursa.Demo.ViewModels;
 
@@ -14,39 +11,36 @@ public partial class NumericUpDownDemoViewModel : ObservableObject
 
 
     private double _oldWidth = 300;
-    [ObservableProperty] private bool _AutoWidth = true;
-    [ObservableProperty] private double _Width = Double.NaN;
-    [ObservableProperty] private uint _Value;
-    [ObservableProperty] private string _FontFamily = "Consolas";
-    [ObservableProperty] private bool _AllowDrag = false;
-    [ObservableProperty] private bool _IsReadOnly = false;
+    [ObservableProperty] private bool _autoWidth = true;
+    [ObservableProperty] private double _width = double.NaN;
+    [ObservableProperty] private uint _value;
+    [ObservableProperty] private string _fontFamily = "Consolas";
+    [ObservableProperty] private bool _allowDrag;
+    [ObservableProperty] private bool _isReadOnly;
 
-    [ObservableProperty] private Array _Array_HorizontalAlignment;
-    [ObservableProperty] private HorizontalAlignment _HorizontalAlignment = HorizontalAlignment.Center;
+    [ObservableProperty] private Array _arrayHorizontalAlignment;
+    [ObservableProperty] private HorizontalAlignment _horizontalAlignment = HorizontalAlignment.Center;
 
-    [ObservableProperty] private Array _Array_HorizontalContentAlignment;
-    [ObservableProperty] private HorizontalAlignment _HorizontalContentAlignment = HorizontalAlignment.Center;
-    [ObservableProperty] private object? _InnerLeftContent = "obj:0x";
-    [ObservableProperty] private string _Watermark = "Water mark showed";
-    [ObservableProperty] private string _FormatString = "X8";
-    [ObservableProperty] private Array _Array_ParsingNumberStyle;
-    [ObservableProperty] private NumberStyles _ParsingNumberStyle = NumberStyles.AllowHexSpecifier;
-    [ObservableProperty] private bool _AllowSpin = true;
-    [ObservableProperty] private bool _ShowButtonSpinner = true;
+    [ObservableProperty] private Array _arrayHorizontalContentAlignment;
+    [ObservableProperty] private HorizontalAlignment _horizontalContentAlignment = HorizontalAlignment.Center;
+    [ObservableProperty] private object? _innerLeftContent = "obj:0x";
+    [ObservableProperty] private string _watermark = "Water mark showed";
+    [ObservableProperty] private string _formatString = "X8";
+    [ObservableProperty] private Array _arrayParsingNumberStyle;
+    [ObservableProperty] private NumberStyles _parsingNumberStyle = NumberStyles.AllowHexSpecifier;
+    [ObservableProperty] private bool _allowSpin = true;
+    [ObservableProperty] private bool _showButtonSpinner = true;
 
-    [ObservableProperty] private UInt32 _Maximum = UInt32.MaxValue;
-    [ObservableProperty] private UInt32 _Minimum = UInt32.MinValue;
-    [ObservableProperty] private UInt32 _Step = 1;
+    [ObservableProperty] private UInt32 _maximum = UInt32.MaxValue;
+    [ObservableProperty] private UInt32 _minimum = UInt32.MinValue;
+    [ObservableProperty] private UInt32 _step = 1;
 
-    [ObservableProperty] private bool _IsEnable = true;
+    [ObservableProperty] private bool _isEnable = true;
 
-    [ObservableProperty] private string _CommandUpdateText = "Command not Execute";
-
-    uint v = 0;
+    [ObservableProperty] private string _commandUpdateText = "Command not Execute";
+    
     [RelayCommand]
-    // void Trythis()
     void Trythis(uint v)
-    // void Trythis(object v)
     {
         CommandUpdateText = $"Command Exe,CommandParameter={v}";
     }
@@ -54,12 +48,9 @@ public partial class NumericUpDownDemoViewModel : ObservableObject
 
     public NumericUpDownDemoViewModel()
     {
-        Array_HorizontalContentAlignment = Enum.GetValues(typeof(HorizontalAlignment));
-        Array_HorizontalAlignment = Enum.GetValues(typeof(HorizontalAlignment));
-        Array_ParsingNumberStyle = Enum.GetValues(typeof(NumberStyles));
-        NumericUIntUpDown numericUIntUpDown;
-        TextBox textBox;
-
+        ArrayHorizontalContentAlignment = Enum.GetValues(typeof(HorizontalAlignment));
+        ArrayHorizontalAlignment = Enum.GetValues(typeof(HorizontalAlignment));
+        ArrayParsingNumberStyle = Enum.GetValues(typeof(NumberStyles));
     }
 
     partial void OnAutoWidthChanged(bool value)
@@ -74,10 +65,4 @@ public partial class NumericUpDownDemoViewModel : ObservableObject
             Width = _oldWidth;
         }
     }
-
-    partial void OnValueChanging(uint oldValue, uint newValue)
-    {
-        // Console.WriteLine(oldValue);
-    }
-
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/ViewModels/PaginationDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/PaginationDemoViewModel.cs
index a64dc9c..748ec17 100644
--- a/demo/Ursa.Demo/ViewModels/PaginationDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/PaginationDemoViewModel.cs
@@ -1,9 +1,6 @@
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.Diagnostics;
 using System.Windows.Input;
 using Avalonia.Collections;
-using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 
 namespace Ursa.Demo.ViewModels;
diff --git a/demo/Ursa.Demo/ViewModels/SkeletonDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/SkeletonDemoViewModel.cs
index 7ee4274..2aa071a 100644
--- a/demo/Ursa.Demo/ViewModels/SkeletonDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/SkeletonDemoViewModel.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Ursa.Demo.ViewModels
+namespace Ursa.Demo.ViewModels
 {
     public class SkeletonDemoViewModel : ViewModelBase
     {
diff --git a/demo/Ursa.Demo/ViewModels/TimeBoxDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/TimeBoxDemoViewModel.cs
index 729b6c5..38b0790 100644
--- a/demo/Ursa.Demo/ViewModels/TimeBoxDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/TimeBoxDemoViewModel.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Net;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 
diff --git a/demo/Ursa.Demo/ViewModels/ToolBarDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/ToolBarDemoViewModel.cs
index 8a04c8a..ce1c71b 100644
--- a/demo/Ursa.Demo/ViewModels/ToolBarDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/ToolBarDemoViewModel.cs
@@ -23,21 +23,21 @@ public partial class ToolBarDemoViewModel : ObservableObject
     {
         Items = new()
         {
-            new ToolBarButtonItemViewModel() { Content = "New", OverflowMode = OverflowMode.AsNeeded },
-            new ToolBarButtonItemViewModel() { Content = "Open" },
-            new ToolBarButtonItemViewModel() { Content = "Save1" },
-            new ToolBarButtonItemViewModel() { Content = "Save2" },
+            new ToolBarButtonItemViewModel { Content = "New", OverflowMode = OverflowMode.AsNeeded },
+            new ToolBarButtonItemViewModel { Content = "Open" },
+            new ToolBarButtonItemViewModel { Content = "Save1" },
+            new ToolBarButtonItemViewModel { Content = "Save2" },
             new ToolBarSeparatorViewModel(),
-            new ToolBarButtonItemViewModel() { Content = "Save3" },
-            new ToolBarButtonItemViewModel() { Content = "Save4" },
-            new ToolBarButtonItemViewModel() { Content = "Save5" },
-            new ToolBarButtonItemViewModel() { Content = "Save6" },
-            new ToolBarButtonItemViewModel() { Content = "Save7" },
+            new ToolBarButtonItemViewModel { Content = "Save3" },
+            new ToolBarButtonItemViewModel { Content = "Save4" },
+            new ToolBarButtonItemViewModel { Content = "Save5" },
+            new ToolBarButtonItemViewModel { Content = "Save6" },
+            new ToolBarButtonItemViewModel { Content = "Save7" },
             new ToolBarSeparatorViewModel(),
-            new ToolBarButtonItemViewModel() { Content = "Save8" },
-            new ToolBarCheckBoxItemViweModel() { Content = "Bold" },
-            new ToolBarCheckBoxItemViweModel() { Content = "Italic", OverflowMode = OverflowMode.Never },
-            new ToolBarComboBoxItemViewModel() { Content = "Font Size", Items = new() { "10", "12", "14" } }
+            new ToolBarButtonItemViewModel { Content = "Save8" },
+            new ToolBarCheckBoxItemViweModel { Content = "Bold" },
+            new ToolBarCheckBoxItemViweModel { Content = "Italic", OverflowMode = OverflowMode.Never },
+            new ToolBarComboBoxItemViewModel { Content = "Font Size", Items = ["10", "12", "14"] }
         };
     }
 }
@@ -49,41 +49,40 @@ public abstract class ToolBarItemViewModel : ObservableObject
 
 public class ToolBarButtonItemViewModel : ToolBarItemViewModel
 {
-    public string Content { get; set; }
-    public ICommand Command { get; set; }
+    public string? Content { get; set; }
+    public ICommand? Command { get; set; }
 
     public ToolBarButtonItemViewModel()
     {
-        Command = new AsyncRelayCommand(async () => { await MessageBox.ShowOverlayAsync(Content); });
+        Command = new AsyncRelayCommand(async () => { await MessageBox.ShowOverlayAsync(Content ?? string.Empty); });
     }
 }
 
 public class ToolBarCheckBoxItemViweModel : ToolBarItemViewModel
 {
-    public string Content { get; set; }
+    public string? Content { get; set; }
     public bool IsChecked { get; set; }
-    public ICommand Command { get; set; }
+    public ICommand? Command { get; set; }
 
     public ToolBarCheckBoxItemViweModel()
     {
-        Command = new AsyncRelayCommand(async () => { await MessageBox.ShowOverlayAsync(Content); });
+        Command = new AsyncRelayCommand(async () => { await MessageBox.ShowOverlayAsync(Content ?? string.Empty); });
     }
 }
 
 public class ToolBarComboBoxItemViewModel : ToolBarItemViewModel
 {
-    public string Content { get; set; }
-    public ObservableCollection<string> Items { get; set; }
+    public string? Content { get; set; }
+    public ObservableCollection<string>? Items { get; set; }
 
-    private string _selectedItem;
-
-    public string SelectedItem
+    private string? _selectedItem;
+    public string? SelectedItem
     {
         get => _selectedItem;
         set
         {
             SetProperty(ref _selectedItem, value);
-            MessageBox.ShowOverlayAsync(value);
+            _ = MessageBox.ShowOverlayAsync(value ?? string.Empty);
         }
     }
 }
diff --git a/demo/Ursa.Demo/ViewModels/VerificationCodeDemoViewModel.cs b/demo/Ursa.Demo/ViewModels/VerificationCodeDemoViewModel.cs
index 5de9705..2b5cc51 100644
--- a/demo/Ursa.Demo/ViewModels/VerificationCodeDemoViewModel.cs
+++ b/demo/Ursa.Demo/ViewModels/VerificationCodeDemoViewModel.cs
@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using System.Windows.Input;
-using Avalonia.Collections;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using Ursa.Controls;
diff --git a/demo/Ursa.Demo/Views/MainView.axaml.cs b/demo/Ursa.Demo/Views/MainView.axaml.cs
index 563f7ea..8ee2660 100644
--- a/demo/Ursa.Demo/Views/MainView.axaml.cs
+++ b/demo/Ursa.Demo/Views/MainView.axaml.cs
@@ -1,7 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Interactivity;
-using Avalonia.Styling;
 
 namespace Ursa.Demo.Views;
 
@@ -11,14 +8,4 @@ public partial class MainView : UserControl
     {
         InitializeComponent();
     }
-
-    private void ToggleButton_OnIsCheckedChanged(object? sender, RoutedEventArgs e)
-    {
-        var app = Application.Current;
-        if (app is not null)
-        {
-            var theme = app.ActualThemeVariant;
-            app.RequestedThemeVariant = theme == ThemeVariant.Dark ? ThemeVariant.Light : ThemeVariant.Dark;
-        }
-    }
 }
\ No newline at end of file
diff --git a/demo/Ursa.Demo/Views/MainWindow.axaml.cs b/demo/Ursa.Demo/Views/MainWindow.axaml.cs
index f6466c3..f5b4304 100644
--- a/demo/Ursa.Demo/Views/MainWindow.axaml.cs
+++ b/demo/Ursa.Demo/Views/MainWindow.axaml.cs
@@ -1,6 +1,3 @@
-using System;
-using Avalonia.Controls;
-using Avalonia.Interactivity;
 using Ursa.Controls;
 
 namespace Ursa.Demo.Views;
diff --git a/demo/Ursa.Demo/Views/SingleView.axaml.cs b/demo/Ursa.Demo/Views/SingleView.axaml.cs
index 7f65e88..5a20b4f 100644
--- a/demo/Ursa.Demo/Views/SingleView.axaml.cs
+++ b/demo/Ursa.Demo/Views/SingleView.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
 
 namespace Ursa.Demo.Views;
 
diff --git a/demo/Ursa.PrismDialogDemo/App.axaml.cs b/demo/Ursa.PrismDialogDemo/App.axaml.cs
index 9e71d4c..33ba459 100644
--- a/demo/Ursa.PrismDialogDemo/App.axaml.cs
+++ b/demo/Ursa.PrismDialogDemo/App.axaml.cs
@@ -1,5 +1,4 @@
 using Avalonia;
-using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Prism.DryIoc;
 using Prism.Ioc;
diff --git a/demo/Ursa.PrismDialogDemo/DefaultDialog.axaml.cs b/demo/Ursa.PrismDialogDemo/DefaultDialog.axaml.cs
index 8a778b4..3f8b624 100644
--- a/demo/Ursa.PrismDialogDemo/DefaultDialog.axaml.cs
+++ b/demo/Ursa.PrismDialogDemo/DefaultDialog.axaml.cs
@@ -1,6 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Controls;
 
 namespace Ursa.PrismDialogDemo;
 
diff --git a/demo/Ursa.PrismDialogDemo/MainWindow.axaml.cs b/demo/Ursa.PrismDialogDemo/MainWindow.axaml.cs
index 6ae5519..08dd3d6 100644
--- a/demo/Ursa.PrismDialogDemo/MainWindow.axaml.cs
+++ b/demo/Ursa.PrismDialogDemo/MainWindow.axaml.cs
@@ -1,6 +1,5 @@
 using Avalonia.Controls;
 using Avalonia.Interactivity;
-using DryIoc;
 using Ursa.Controls;
 using Ursa.Controls.Options;
 using Ursa.PrismExtension;
@@ -22,6 +21,7 @@ public partial class MainWindow : Window
         _drawerService = drawerService;
     }
 
+    // ReSharper disable once UnusedParameter.Local
     private void OverlayDialogButton_OnClick(object? sender, RoutedEventArgs e)
     {
         _overlayDialogService.ShowModal("Default", null, null, new OverlayDialogOptions()
@@ -30,6 +30,7 @@ public partial class MainWindow : Window
         });
     }
 
+    // ReSharper disable once UnusedParameter.Local
     private void AloneDialogButton_OnClick(object? sender, RoutedEventArgs e)
     {
         _aloneDialogService.ShowModal("Default", null, null, new DialogOptions()
@@ -38,6 +39,7 @@ public partial class MainWindow : Window
         });
     }
 
+    // ReSharper disable once UnusedParameter.Local
     private void DrawerButton_OnClick(object? sender, RoutedEventArgs e)
     {
         _drawerService.ShowModal("Default", null, null, new DrawerOptions()
diff --git a/src/Ursa.PrismExtension/IUrsaOverlayDialogService.cs b/src/Ursa.PrismExtension/IUrsaOverlayDialogService.cs
index fd282e4..17ecc71 100644
--- a/src/Ursa.PrismExtension/IUrsaOverlayDialogService.cs
+++ b/src/Ursa.PrismExtension/IUrsaOverlayDialogService.cs
@@ -1,5 +1,4 @@
-using Avalonia.Controls;
-using Ursa.Controls;
+using Ursa.Controls;
 
 namespace Ursa.PrismExtension;
 
diff --git a/src/Ursa.Themes.Semi/Controls/Badge.axaml b/src/Ursa.Themes.Semi/Controls/Badge.axaml
index 099384f..ff7ab9b 100644
--- a/src/Ursa.Themes.Semi/Controls/Badge.axaml
+++ b/src/Ursa.Themes.Semi/Controls/Badge.axaml
@@ -70,7 +70,7 @@
         </Setter>
 
         <Style Selector="^[Dot=True]">
-            <Setter Property="u:Badge.Template">
+            <Setter Property="Template">
                 <ControlTemplate TargetType="{x:Type u:Badge}">
                     <Grid
                         HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
diff --git a/src/Ursa.Themes.Semi/Controls/Banner.axaml b/src/Ursa.Themes.Semi/Controls/Banner.axaml
index 36cf067..8624194 100644
--- a/src/Ursa.Themes.Semi/Controls/Banner.axaml
+++ b/src/Ursa.Themes.Semi/Controls/Banner.axaml
@@ -69,54 +69,54 @@
         </Setter>
         <Style Selector="^[Type=Information]">
             <Style Selector="^.Bordered /template/ Border#PART_Container">
-                <Setter Property="Border.CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
+                <Setter Property="CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
                 <Setter Property="BorderBrush" Value="{DynamicResource BannerInformationBorderBrush}" />
             </Style>
             <Style Selector="^ /template/ Border#PART_Container">
                 <Setter Property="Background" Value="{DynamicResource BannerInformationBackground}" />
             </Style>
             <Style Selector="^ /template/ PathIcon#PART_BuildInIcon">
-                <Setter Property="PathIcon.Data" Value="{DynamicResource BannerInformationIconGeometry}" />
-                <Setter Property="PathIcon.Foreground" Value="{DynamicResource BannerInformationBorderBrush}" />
+                <Setter Property="Data" Value="{DynamicResource BannerInformationIconGeometry}" />
+                <Setter Property="Foreground" Value="{DynamicResource BannerInformationBorderBrush}" />
             </Style>
         </Style>
         <Style Selector="^[Type=Success]">
             <Style Selector="^.Bordered /template/ Border#PART_Container">
-                <Setter Property="Border.CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
+                <Setter Property="CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
                 <Setter Property="BorderBrush" Value="{DynamicResource BannerSuccessBorderBrush}" />
             </Style>
             <Style Selector="^ /template/ Border#PART_Container">
                 <Setter Property="Background" Value="{DynamicResource BannerSuccessBackground}" />
             </Style>
             <Style Selector="^ /template/ PathIcon#PART_BuildInIcon">
-                <Setter Property="PathIcon.Data" Value="{DynamicResource BannerSuccessIconGeometry}" />
-                <Setter Property="PathIcon.Foreground" Value="{DynamicResource BannerSuccessBorderBrush}" />
+                <Setter Property="Data" Value="{DynamicResource BannerSuccessIconGeometry}" />
+                <Setter Property="Foreground" Value="{DynamicResource BannerSuccessBorderBrush}" />
             </Style>
         </Style>
         <Style Selector="^[Type=Warning]">
             <Style Selector="^.Bordered /template/ Border#PART_Container">
-                <Setter Property="Border.CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
+                <Setter Property="CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
                 <Setter Property="BorderBrush" Value="{DynamicResource BannerWarningBorderBrush}" />
             </Style>
             <Style Selector="^ /template/ Border#PART_Container">
                 <Setter Property="Background" Value="{DynamicResource BannerWarningBackground}" />
             </Style>
             <Style Selector="^ /template/ PathIcon#PART_BuildInIcon">
-                <Setter Property="PathIcon.Data" Value="{DynamicResource BannerWarningIconGeometry}" />
-                <Setter Property="PathIcon.Foreground" Value="{DynamicResource BannerWarningBorderBrush}" />
+                <Setter Property="Data" Value="{DynamicResource BannerWarningIconGeometry}" />
+                <Setter Property="Foreground" Value="{DynamicResource BannerWarningBorderBrush}" />
             </Style>
         </Style>
         <Style Selector="^[Type=Error]">
             <Style Selector="^.Bordered /template/ Border#PART_Container">
-                <Setter Property="Border.CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
+                <Setter Property="CornerRadius" Value="{DynamicResource BannerCornerRadius}" />
                 <Setter Property="BorderBrush" Value="{DynamicResource BannerErrorBorderBrush}" />
             </Style>
             <Style Selector="^ /template/ Border#PART_Container">
                 <Setter Property="Background" Value="{DynamicResource BannerErrorBackground}" />
             </Style>
             <Style Selector="^ /template/ PathIcon#PART_BuildInIcon">
-                <Setter Property="PathIcon.Data" Value="{DynamicResource BannerErrorIconGeometry}" />
-                <Setter Property="PathIcon.Foreground" Value="{DynamicResource BannerErrorBorderBrush}" />
+                <Setter Property="Data" Value="{DynamicResource BannerErrorIconGeometry}" />
+                <Setter Property="Foreground" Value="{DynamicResource BannerErrorBorderBrush}" />
             </Style>
         </Style>
     </ControlTheme>
diff --git a/src/Ursa.Themes.Semi/Controls/DatePicker.axaml b/src/Ursa.Themes.Semi/Controls/DatePicker.axaml
index 6ddb92c..ae353b1 100644
--- a/src/Ursa.Themes.Semi/Controls/DatePicker.axaml
+++ b/src/Ursa.Themes.Semi/Controls/DatePicker.axaml
@@ -1,7 +1,6 @@
 <ResourceDictionary
     xmlns="https://github.com/avaloniaui"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:contracts="https://irihi.tech/shared"
     xmlns:u="https://irihi.tech/ursa">
     <!--  Add Resources Here  -->
     <ControlTheme x:Key="{x:Type u:DatePicker}" TargetType="u:DatePicker">
diff --git a/src/Ursa.Themes.Semi/Controls/Dialog.axaml b/src/Ursa.Themes.Semi/Controls/Dialog.axaml
index ca5d11e..66a500a 100644
--- a/src/Ursa.Themes.Semi/Controls/Dialog.axaml
+++ b/src/Ursa.Themes.Semi/Controls/Dialog.axaml
@@ -165,7 +165,6 @@
                             <ScrollViewer Grid.Row="1">
                                 <ContentPresenter
                                     Name="PART_ContentPresenter"
-                                    Grid.Row="1"
                                     HorizontalAlignment="Center"
                                     VerticalAlignment="Center"
                                     Margin="24,8"
diff --git a/src/Ursa.Themes.Semi/Controls/Drawer.axaml b/src/Ursa.Themes.Semi/Controls/Drawer.axaml
index ca28bf3..dff0cd2 100644
--- a/src/Ursa.Themes.Semi/Controls/Drawer.axaml
+++ b/src/Ursa.Themes.Semi/Controls/Drawer.axaml
@@ -85,7 +85,6 @@
                             <ScrollViewer Grid.Row="1">
                                 <ContentPresenter
                                     Name="PART_ContentPresenter"
-                                    Grid.Row="1"
                                     Margin="24,8"
                                     Content="{TemplateBinding Content}" />
                             </ScrollViewer>
diff --git a/src/Ursa.Themes.Semi/Controls/IPv4Box.axaml b/src/Ursa.Themes.Semi/Controls/IPv4Box.axaml
index 4cd290f..1c9e18a 100644
--- a/src/Ursa.Themes.Semi/Controls/IPv4Box.axaml
+++ b/src/Ursa.Themes.Semi/Controls/IPv4Box.axaml
@@ -113,10 +113,10 @@
             </ControlTemplate>
         </Setter>
         <Style Selector="^:pointerover /template/ Border#PART_Border">
-            <Setter Property="Border.Background" Value="{DynamicResource IPv4BoxPointeroverBackground}" />
+            <Setter Property="Background" Value="{DynamicResource IPv4BoxPointeroverBackground}" />
         </Style>
         <Style Selector="^:pressed /template/ Border#PART_Border">
-            <Setter Property="Border.Background" Value="{DynamicResource IPv4BoxPressedBackground}" />
+            <Setter Property="Background" Value="{DynamicResource IPv4BoxPressedBackground}" />
         </Style>
         <Style Selector="^:focus-within">
             <Setter Property="Border.BorderBrush" Value="{DynamicResource IPv4BoxFocusBorderBrush}" />
diff --git a/src/Ursa.Themes.Semi/Controls/IconButton.axaml b/src/Ursa.Themes.Semi/Controls/IconButton.axaml
index 0fe0787..40309a9 100644
--- a/src/Ursa.Themes.Semi/Controls/IconButton.axaml
+++ b/src/Ursa.Themes.Semi/Controls/IconButton.axaml
@@ -59,7 +59,7 @@
                         </Panel>
                         <ContentPresenter
                             Name="PART_ContentPresenter"
-                            Grid.Column="1"
+                            Grid.Row="0" Grid.Column="1"
                             Margin="8 0 0 0"
                             HorizontalAlignment="Center"
                             VerticalAlignment="Center"
diff --git a/src/Ursa.Themes.Semi/Controls/Loading.axaml b/src/Ursa.Themes.Semi/Controls/Loading.axaml
index 1732438..38c53e5 100644
--- a/src/Ursa.Themes.Semi/Controls/Loading.axaml
+++ b/src/Ursa.Themes.Semi/Controls/Loading.axaml
@@ -47,14 +47,14 @@
             </ControlTemplate>
         </Setter>
         <Style Selector="^.Small /template/ Arc#PART_Arc">
-            <Setter Property="Arc.Width" Value="14" />
-            <Setter Property="Arc.Height" Value="14" />
-            <Setter Property="Arc.StrokeThickness" Value="2" />
+            <Setter Property="Width" Value="14" />
+            <Setter Property="Height" Value="14" />
+            <Setter Property="StrokeThickness" Value="2" />
         </Style>
         <Style Selector="^.Large /template/ Arc#PART_Arc">
-            <Setter Property="Arc.Width" Value="32" />
-            <Setter Property="Arc.Height" Value="32" />
-            <Setter Property="Arc.StrokeThickness" Value="5" />
+            <Setter Property="Width" Value="32" />
+            <Setter Property="Height" Value="32" />
+            <Setter Property="StrokeThickness" Value="5" />
         </Style>
     </ControlTheme>
 
diff --git a/src/Ursa.Themes.Semi/Controls/NumberDisplayer.axaml b/src/Ursa.Themes.Semi/Controls/NumberDisplayer.axaml
index 7b34b4b..50c207e 100644
--- a/src/Ursa.Themes.Semi/Controls/NumberDisplayer.axaml
+++ b/src/Ursa.Themes.Semi/Controls/NumberDisplayer.axaml
@@ -1,7 +1,6 @@
 <ResourceDictionary
     xmlns="https://github.com/avaloniaui"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:converters="clr-namespace:Ursa.Converters;assembly=Ursa"
     xmlns:u="https://irihi.tech/ursa">
     <!--  Add Resources Here  -->
     <ControlTheme x:Key="{x:Type u:NumberDisplayerBase}" TargetType="u:NumberDisplayerBase">
diff --git a/src/Ursa.Themes.Semi/Controls/Pagination.axaml b/src/Ursa.Themes.Semi/Controls/Pagination.axaml
index f190de4..41cdecb 100644
--- a/src/Ursa.Themes.Semi/Controls/Pagination.axaml
+++ b/src/Ursa.Themes.Semi/Controls/Pagination.axaml
@@ -74,13 +74,13 @@
             </ControlTemplate>
         </Setter>
         <Style Selector="^:pointerover">
-            <Setter Property="u:PaginationButton.Background" Value="{DynamicResource PaginationButtonPointeroverBackground}" />
+            <Setter Property="Background" Value="{DynamicResource PaginationButtonPointeroverBackground}" />
         </Style>
         <Style Selector="^:pressed">
-            <Setter Property="u:PaginationButton.Background" Value="{DynamicResource PaginationButtonPressedBackground}" />
+            <Setter Property="Background" Value="{DynamicResource PaginationButtonPressedBackground}" />
         </Style>
         <Style Selector="^:left">
-            <Setter Property="u:PaginationButton.Content">
+            <Setter Property="Content">
                 <Template>
                     <PathIcon
                         Width="12"
@@ -90,7 +90,7 @@
                 </Template>
             </Setter>
             <Style Selector="^:pointerover">
-                <Setter Property="u:PaginationButton.Content">
+                <Setter Property="Content">
                     <Template>
                         <PathIcon
                             Width="12"
@@ -102,7 +102,7 @@
             </Style>
         </Style>
         <Style Selector="^:right">
-            <Setter Property="u:PaginationButton.Content">
+            <Setter Property="Content">
                 <Template>
                     <PathIcon
                         Width="12"
@@ -112,7 +112,7 @@
                 </Template>
             </Setter>
             <Style Selector="^:pointerover">
-                <Setter Property="u:PaginationButton.Content">
+                <Setter Property="Content">
                     <Template>
                         <PathIcon
                             Width="12"
diff --git a/src/Ursa.Themes.Semi/Controls/TagInput.axaml b/src/Ursa.Themes.Semi/Controls/TagInput.axaml
index 0b25a9e..6357f4a 100644
--- a/src/Ursa.Themes.Semi/Controls/TagInput.axaml
+++ b/src/Ursa.Themes.Semi/Controls/TagInput.axaml
@@ -52,10 +52,10 @@
             <Setter Property="IsVisible" Value="True"></Setter>
         </Style>
         <Style Selector="^:pointerover /template/ Border#PART_BackgroundBorder">
-            <Setter Property="Border.Background" Value="{DynamicResource TextBoxPointeroverBackground}" />
+            <Setter Property="Background" Value="{DynamicResource TextBoxPointeroverBackground}" />
         </Style>
         <Style Selector="^:focus-within /template/ Border#PART_BackgroundBorder">
-            <Setter Property="Border.BorderBrush" Value="{DynamicResource TextBoxFocusBorderBrush}" />
+            <Setter Property="BorderBrush" Value="{DynamicResource TextBoxFocusBorderBrush}" />
         </Style>
     </ControlTheme>
 
diff --git a/src/Ursa.Themes.Semi/Controls/TimePicker.axaml b/src/Ursa.Themes.Semi/Controls/TimePicker.axaml
index b640b65..04e065b 100644
--- a/src/Ursa.Themes.Semi/Controls/TimePicker.axaml
+++ b/src/Ursa.Themes.Semi/Controls/TimePicker.axaml
@@ -1,7 +1,6 @@
 <ResourceDictionary
     xmlns="https://github.com/avaloniaui"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:converters="clr-namespace:Ursa.Converters;assembly=Ursa"
     xmlns:iri="https://irihi.tech/shared"
     xmlns:u="https://irihi.tech/ursa">
     <!--  Add Resources Here  -->
diff --git a/src/Ursa.Themes.Semi/Controls/Timeline.axaml b/src/Ursa.Themes.Semi/Controls/Timeline.axaml
index 913e62c..b82087f 100644
--- a/src/Ursa.Themes.Semi/Controls/Timeline.axaml
+++ b/src/Ursa.Themes.Semi/Controls/Timeline.axaml
@@ -110,7 +110,7 @@
             </ControlTemplate>
         </Setter>
         <Style Selector="^:last /template/ Rectangle.end">
-            <Setter Property="Rectangle.Fill" Value="Transparent" />
+            <Setter Property="Fill" Value="Transparent" />
         </Style>
         <Style Selector="^:empty-icon /template/ Ellipse#PART_DefaultIcon">
             <Setter Property="IsVisible" Value="True"/>
diff --git a/src/Ursa.Themes.Semi/Converters/BooleansToOpacityConverter.cs b/src/Ursa.Themes.Semi/Converters/BooleansToOpacityConverter.cs
index 0272448..f172fe9 100644
--- a/src/Ursa.Themes.Semi/Converters/BooleansToOpacityConverter.cs
+++ b/src/Ursa.Themes.Semi/Converters/BooleansToOpacityConverter.cs
@@ -5,7 +5,7 @@ namespace Ursa.Themes.Semi.Converters;
 
 public class BooleansToOpacityConverter: IValueConverter
 {
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is bool b)
         {
@@ -14,7 +14,7 @@ public class BooleansToOpacityConverter: IValueConverter
         return 1;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/src/Ursa.Themes.Semi/Converters/BrushToColorConverter.cs b/src/Ursa.Themes.Semi/Converters/BrushToColorConverter.cs
index e8074a2..13f072c 100644
--- a/src/Ursa.Themes.Semi/Converters/BrushToColorConverter.cs
+++ b/src/Ursa.Themes.Semi/Converters/BrushToColorConverter.cs
@@ -1,5 +1,4 @@
 using System.Globalization;
-using Avalonia;
 using Avalonia.Data.Converters;
 using Avalonia.Media;
 
@@ -7,7 +6,7 @@ namespace Ursa.Themes.Semi.Converters;
 
 public class BrushToColorConverter: IValueConverter
 {
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is ISolidColorBrush b)
         {
@@ -16,7 +15,7 @@ public class BrushToColorConverter: IValueConverter
         return Colors.Transparent;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/src/Ursa.Themes.Semi/Converters/ClockHandLengthConverter.cs b/src/Ursa.Themes.Semi/Converters/ClockHandLengthConverter.cs
index 6715eef..68e890a 100644
--- a/src/Ursa.Themes.Semi/Converters/ClockHandLengthConverter.cs
+++ b/src/Ursa.Themes.Semi/Converters/ClockHandLengthConverter.cs
@@ -8,8 +8,6 @@ public class ClockHandLengthConverter(double ratio) : IValueConverter
     public static ClockHandLengthConverter Hour { get; } = new(1-0.618);
     public static ClockHandLengthConverter Minute { get; } = new(0.618);
     public static ClockHandLengthConverter Second { get; } = new(1);
-    
-    private double _ratio = ratio;
 
     public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
@@ -20,7 +18,7 @@ public class ClockHandLengthConverter(double ratio) : IValueConverter
         return 0.0;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/src/Ursa.Themes.Semi/Converters/TimelineItemTypeToIconForegroundConverter.cs b/src/Ursa.Themes.Semi/Converters/TimelineItemTypeToIconForegroundConverter.cs
index 2b2d1ab..a228e9f 100644
--- a/src/Ursa.Themes.Semi/Converters/TimelineItemTypeToIconForegroundConverter.cs
+++ b/src/Ursa.Themes.Semi/Converters/TimelineItemTypeToIconForegroundConverter.cs
@@ -1,6 +1,5 @@
 using System.Globalization;
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Data.Converters;
 using Avalonia.Media;
 using Ursa.Controls;
@@ -55,7 +54,7 @@ public class TimelineItemTypeToIconForegroundConverter: AvaloniaObject, IMultiVa
     }
 
 
-    public object? Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
     {
         if (values[0] is TimelineItemType type)
         {
diff --git a/src/Ursa.Themes.Semi/Index.axaml.cs b/src/Ursa.Themes.Semi/Index.axaml.cs
index 9151917..603e65a 100644
--- a/src/Ursa.Themes.Semi/Index.axaml.cs
+++ b/src/Ursa.Themes.Semi/Index.axaml.cs
@@ -20,10 +20,10 @@ public class SemiTheme: Styles
     
     private static readonly ResourceDictionary _defaultResource = new zh_cn();
     
-    private readonly IServiceProvider? sp;
+    private readonly IServiceProvider? _sp;
     public SemiTheme(IServiceProvider? provider = null)
     {
-        sp = provider;
+        _sp = provider;
         AvaloniaXamlLoader.Load(provider, this);
     }
 
diff --git a/src/Ursa/Controls/Badge.cs b/src/Ursa/Controls/Badge.cs
index 23124ed..6092f97 100644
--- a/src/Ursa/Controls/Badge.cs
+++ b/src/Ursa/Controls/Badge.cs
@@ -61,7 +61,7 @@ public class Badge: HeaderedContentControl
 
     static Badge()
     {
-        HeaderProperty.Changed.AddClassHandler<Badge>((badge, args) => badge.UpdateBadgePosition());
+        HeaderProperty.Changed.AddClassHandler<Badge>((badge, _) => badge.UpdateBadgePosition());
     }
 
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
@@ -86,7 +86,7 @@ public class Badge: HeaderedContentControl
     {
         var vertical = CornerPosition is CornerPosition.BottomLeft or CornerPosition.BottomRight ? 1 : -1;
         var horizontal = CornerPosition is CornerPosition.TopRight or CornerPosition.BottomRight ? 1 : -1;
-        if (_badgeContainer is not null && base.Presenter?.Child is not null)
+        if (_badgeContainer is not null && Presenter?.Child is not null)
         {
             _badgeContainer.RenderTransform = new TransformGroup()
             {
diff --git a/src/Ursa/Controls/Banner/Banner.cs b/src/Ursa/Controls/Banner/Banner.cs
index abdf373..f852701 100644
--- a/src/Ursa/Controls/Banner/Banner.cs
+++ b/src/Ursa/Controls/Banner/Banner.cs
@@ -3,9 +3,7 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Notifications;
 using Avalonia.Controls.Primitives;
-using Avalonia.Controls.Templates;
 using Avalonia.Interactivity;
-using Avalonia.Metadata;
 using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
@@ -63,7 +61,7 @@ public class Banner: HeaderedContentControl
         Button.ClickEvent.AddHandler(OnCloseClick, _closeButton);
     }
 
-    private void OnCloseClick(object sender, RoutedEventArgs args)
+    private void OnCloseClick(object? sender, RoutedEventArgs args)
     {
         IsVisible = false;
     }
diff --git a/src/Ursa/Controls/Breadcrumb/BreadcrumbItem.cs b/src/Ursa/Controls/Breadcrumb/BreadcrumbItem.cs
index 64aaf9f..ea8edae 100644
--- a/src/Ursa/Controls/Breadcrumb/BreadcrumbItem.cs
+++ b/src/Ursa/Controls/Breadcrumb/BreadcrumbItem.cs
@@ -4,7 +4,6 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Templates;
 using Avalonia.Input;
-using Avalonia.LogicalTree;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/Buttons/ButtonGroup.cs b/src/Ursa/Controls/Buttons/ButtonGroup.cs
index 0c8aa6b..a4d6be3 100644
--- a/src/Ursa/Controls/Buttons/ButtonGroup.cs
+++ b/src/Ursa/Controls/Buttons/ButtonGroup.cs
@@ -1,10 +1,6 @@
-using System.Net.Http.Headers;
 using Avalonia;
-using Avalonia.Collections;
 using Avalonia.Controls;
-using Avalonia.Controls.Primitives;
 using Avalonia.Data;
-using Avalonia.Media;
 using Avalonia.Metadata;
 using Irihi.Avalonia.Shared.Helpers;
 
diff --git a/src/Ursa/Controls/Buttons/IconButton.cs b/src/Ursa/Controls/Buttons/IconButton.cs
index e5e042a..68b1e26 100644
--- a/src/Ursa/Controls/Buttons/IconButton.cs
+++ b/src/Ursa/Controls/Buttons/IconButton.cs
@@ -3,7 +3,6 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
-using Avalonia.Layout;
 using Ursa.Common;
 
 namespace Ursa.Controls;
diff --git a/src/Ursa/Controls/Clock/Clock.cs b/src/Ursa/Controls/Clock/Clock.cs
index c2d921a..f6c9176 100644
--- a/src/Ursa/Controls/Clock/Clock.cs
+++ b/src/Ursa/Controls/Clock/Clock.cs
@@ -156,7 +156,7 @@ public class Clock : TemplatedControl
 
     private CancellationTokenSource _cts = new CancellationTokenSource();
 
-    private async void OnTimeChanged(AvaloniaPropertyChangedEventArgs<DateTime> args)
+    private void OnTimeChanged(AvaloniaPropertyChangedEventArgs<DateTime> args)
     {
         var oldSeconds = args.OldValue.Value.Second;
         var time = args.NewValue.Value;
@@ -179,8 +179,14 @@ public class Clock : TemplatedControl
             _cts.Cancel();
             _cts.Dispose();
             _cts = new CancellationTokenSource();
-            (_secondsAnimation.Children[0].Setters[0] as Setter).Value = oldSecondAngle;
-            (_secondsAnimation.Children[1].Setters[0] as Setter).Value = secondAngle;
+            if (_secondsAnimation.Children[0].Setters[0] is Setter start)
+            {
+                start.Value = oldSecondAngle;
+            }
+            if (_secondsAnimation.Children[1].Setters[0] is Setter end)
+            {
+                end.Value = secondAngle;
+            }
             _secondsAnimation.RunAsync(this, _cts.Token);
         }
     }
diff --git a/src/Ursa/Controls/ComboBox/MultiComboBox.cs b/src/Ursa/Controls/ComboBox/MultiComboBox.cs
index 83381a9..78260a5 100644
--- a/src/Ursa/Controls/ComboBox/MultiComboBox.cs
+++ b/src/Ursa/Controls/ComboBox/MultiComboBox.cs
@@ -6,10 +6,8 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
-using Avalonia.Data.Converters;
 using Avalonia.Input;
 using Avalonia.Interactivity;
-using Avalonia.LogicalTree;
 using Irihi.Avalonia.Shared.Helpers;
 using Irihi.Avalonia.Shared.Contracts;
 
@@ -145,7 +143,7 @@ public class MultiComboBox: SelectingItemsControl, IInnerContentControl
         PseudoClasses.Set(PC_Empty, SelectedItems?.Count == 0);
     }
 
-    private void OnBackgroundPointerPressed(object sender, PointerPressedEventArgs e)
+    private void OnBackgroundPointerPressed(object? sender, PointerPressedEventArgs e)
     {
         SetCurrentValue(IsDropDownOpenProperty, !IsDropDownOpen);
     }
diff --git a/src/Ursa/Controls/ComboBox/MultiComboBoxItem.cs b/src/Ursa/Controls/ComboBox/MultiComboBoxItem.cs
index 17b145c..74f4cb8 100644
--- a/src/Ursa/Controls/ComboBox/MultiComboBoxItem.cs
+++ b/src/Ursa/Controls/ComboBox/MultiComboBoxItem.cs
@@ -1,5 +1,4 @@
-using System.Windows.Input;
-using Avalonia;
+using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Mixins;
 using Avalonia.Input;
diff --git a/src/Ursa/Controls/ComboBox/TreeComboBoxItem.cs b/src/Ursa/Controls/ComboBox/TreeComboBoxItem.cs
index cab3e1e..fae2526 100644
--- a/src/Ursa/Controls/ComboBox/TreeComboBoxItem.cs
+++ b/src/Ursa/Controls/ComboBox/TreeComboBoxItem.cs
@@ -6,8 +6,6 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.LogicalTree;
-using Avalonia.Media;
-using Avalonia.Media.TextFormatting;
 using Irihi.Avalonia.Shared.Common;
 using Irihi.Avalonia.Shared.Helpers;
 
@@ -16,7 +14,6 @@ namespace Ursa.Controls;
 [TemplatePart(PartNames.PART_Header, typeof(Control))]
 public class TreeComboBoxItem: HeaderedItemsControl, ISelectable
 {
-    private Control? _header;
     private TreeComboBox? _treeComboBox;
     public TreeComboBox? Owner => _treeComboBox;
     
@@ -58,7 +55,7 @@ public class TreeComboBoxItem: HeaderedItemsControl, ISelectable
     {
         base.OnApplyTemplate(e);
         DoubleTappedEvent.RemoveHandler(OnDoubleTapped, this);
-        _header = e.NameScope.Find<Control>(PartNames.PART_Header);
+        e.NameScope.Find<Control>(PartNames.PART_Header);
         DoubleTappedEvent.AddHandler(OnDoubleTapped, RoutingStrategies.Tunnel, true, this);
     }
 
@@ -77,7 +74,7 @@ public class TreeComboBoxItem: HeaderedItemsControl, ISelectable
         }
     }
 
-    private void OnDoubleTapped(object sender, TappedEventArgs e)
+    private void OnDoubleTapped(object? sender, TappedEventArgs e)
     {
         if (this.ItemCount <= 0) return;
         this.SetCurrentValue(IsExpandedProperty, !IsExpanded);
@@ -86,8 +83,6 @@ public class TreeComboBoxItem: HeaderedItemsControl, ISelectable
 
     protected override bool NeedsContainerOverride(object? item, int index, out object? recycleKey)
     {
-        TreeViewItem t = new TreeViewItem();
-        ComboBox c = new ComboBox();
         return EnsureParent().NeedsContainerInternal(item, index, out recycleKey);
     }
 
diff --git a/src/Ursa/Controls/ControlClassesInput/ControlClassesInput.cs b/src/Ursa/Controls/ControlClassesInput/ControlClassesInput.cs
index a9251d9..10bf8ef 100644
--- a/src/Ursa/Controls/ControlClassesInput/ControlClassesInput.cs
+++ b/src/Ursa/Controls/ControlClassesInput/ControlClassesInput.cs
@@ -1,7 +1,6 @@
 using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using Avalonia;
-using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 
@@ -9,9 +8,9 @@ namespace Ursa.Controls;
 
 public class ControlClassesInput: TemplatedControl
 {
-    LinkedList<List<string>> _history = new();
-    LinkedList<List<string>> _undoHistory = new();
-    private bool _disableHistory = false;
+    private readonly LinkedList<List<string>> _history = [];
+    private readonly LinkedList<List<string>> _undoHistory = [];
+    private bool _disableHistory;
     
     public int CountOfHistoricalRecord { get; set; } = 10;
     
@@ -34,12 +33,12 @@ public class ControlClassesInput: TemplatedControl
     }
 
 
-    private ObservableCollection<string> _targetClasses;
+    private ObservableCollection<string>? _targetClasses;
 
-    internal static readonly DirectProperty<ControlClassesInput, ObservableCollection<string>> TargetClassesProperty = AvaloniaProperty.RegisterDirect<ControlClassesInput, ObservableCollection<string>>(
+    internal static readonly DirectProperty<ControlClassesInput, ObservableCollection<string>?> TargetClassesProperty = AvaloniaProperty.RegisterDirect<ControlClassesInput, ObservableCollection<string>?>(
         nameof(TargetClasses), o => o.TargetClasses, (o, v) => o.TargetClasses = v);
 
-    public ObservableCollection<string> TargetClasses
+    public ObservableCollection<string>? TargetClasses
     {
         get => _targetClasses;
         set => SetAndRaise(TargetClassesProperty, ref _targetClasses, value);
@@ -53,14 +52,13 @@ public class ControlClassesInput: TemplatedControl
 
     static ControlClassesInput()
     {
-        TargetClassesProperty.Changed.AddClassHandler<ControlClassesInput, ObservableCollection<string>>((o,e)=>o.OnClassesChanged(e));
+        TargetClassesProperty.Changed.AddClassHandler<ControlClassesInput, ObservableCollection<string>?>((o,e)=>o.OnClassesChanged(e));
         SourceProperty.Changed.AddClassHandler<StyledElement, ControlClassesInput?>(HandleSourceChange);
     }
 
     public ControlClassesInput()
     {
         TargetClasses = new ObservableCollection<string>();
-        //TargetClasses.CollectionChanged += InccOnCollectionChanged;
     }
 
     private List<StyledElement> _targets = new();
@@ -83,7 +81,6 @@ public class ControlClassesInput: TemplatedControl
         if (newValue is null)
         {
             SaveHistory(new List<string>(), true);
-            return;
         }
         else
         {
@@ -93,11 +90,10 @@ public class ControlClassesInput: TemplatedControl
             {
                 incc.CollectionChanged+=InccOnCollectionChanged;
             }
-            return;
         }
     }
 
-    private void InccOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+    private void InccOnCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
     {
         if(_disableHistory) return;
         SaveHistory(TargetClasses?.ToList() ?? new List<string>(), true);
@@ -123,7 +119,7 @@ public class ControlClassesInput: TemplatedControl
         }
         else
         {
-            strings = _history.Last.Value;
+            strings = _history.Last?.Value ?? [];
         }
 
         if (!fromInput)
@@ -146,10 +142,10 @@ public class ControlClassesInput: TemplatedControl
         _history.RemoveLast();
         _undoHistory.AddFirst(node);
         _disableHistory = true;
-        TargetClasses.Clear();
+        TargetClasses?.Clear();
         foreach (var value in _history.Last.Value)
         {
-            TargetClasses.Add(value);
+            TargetClasses?.Add(value);
         }
         _disableHistory = false;
         SetClassesToTarget(false);
@@ -161,10 +157,10 @@ public class ControlClassesInput: TemplatedControl
         _undoHistory.RemoveFirst();
         _history.AddLast(node);
         _disableHistory = true;
-        TargetClasses.Clear();
+        TargetClasses?.Clear();
         foreach (var value in _history.Last.Value)
         {
-            TargetClasses.Add(value);
+            TargetClasses?.Add(value);
         }
         _disableHistory = false;
         SetClassesToTarget(false);
diff --git a/src/Ursa/Controls/DateTimePicker/CalendarDayButton.cs b/src/Ursa/Controls/DateTimePicker/CalendarDayButton.cs
index a4bdb5a..ab20e41 100644
--- a/src/Ursa/Controls/DateTimePicker/CalendarDayButton.cs
+++ b/src/Ursa/Controls/DateTimePicker/CalendarDayButton.cs
@@ -1,7 +1,6 @@
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Mixins;
-using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Common;
diff --git a/src/Ursa/Controls/DateTimePicker/CalendarView.cs b/src/Ursa/Controls/DateTimePicker/CalendarView.cs
index 290fc7f..f2509e1 100644
--- a/src/Ursa/Controls/DateTimePicker/CalendarView.cs
+++ b/src/Ursa/Controls/DateTimePicker/CalendarView.cs
@@ -1,6 +1,5 @@
 using System.Diagnostics;
 using System.Globalization;
-using System.Runtime.CompilerServices;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
@@ -167,7 +166,7 @@ public class CalendarView : TemplatedControl
         UpdateYearButtons();
     }
 
-    private void OnFastNext(object sender, RoutedEventArgs e)
+    private void OnFastNext(object? sender, RoutedEventArgs e)
     {
         if (Mode == CalendarViewMode.Month)
         {
@@ -176,7 +175,7 @@ public class CalendarView : TemplatedControl
         }
     }
 
-    private void OnNext(object sender, RoutedEventArgs e)
+    private void OnNext(object? sender, RoutedEventArgs e)
     {
         if (Mode == CalendarViewMode.Month)
         {
@@ -200,7 +199,7 @@ public class CalendarView : TemplatedControl
         }
     }
 
-    private void OnPrevious(object sender, RoutedEventArgs e)
+    private void OnPrevious(object? sender, RoutedEventArgs e)
     {
         if (Mode == CalendarViewMode.Month)
         {
@@ -224,7 +223,7 @@ public class CalendarView : TemplatedControl
         }
     }
 
-    private void OnFastPrevious(object sender, RoutedEventArgs e)
+    private void OnFastPrevious(object? sender, RoutedEventArgs e)
     {
         if (Mode == CalendarViewMode.Month)
         {
@@ -238,7 +237,7 @@ public class CalendarView : TemplatedControl
     /// </summary>
     /// <param name="sender"></param>
     /// <param name="e"></param>
-    private void OnHeaderButtonClick(object sender, RoutedEventArgs e)
+    private void OnHeaderButtonClick(object? sender, RoutedEventArgs e)
     {
         // Header button should be hidden in Month mode.
         if (Mode == CalendarViewMode.Month) return;
@@ -319,7 +318,7 @@ public class CalendarView : TemplatedControl
         if (_monthGrid is null || Mode != CalendarViewMode.Month) return;
         var children = _monthGrid.Children;
         var info = DateTimeHelper.GetCurrentDateTimeFormatInfo();
-        var date = new DateTime(ContextDate.Year ?? ContextDate.StartYear.Value, ContextDate.Month.Value, 1);
+        var date = new DateTime(ContextDate.Year ?? ContextDate.StartYear!.Value, ContextDate.Month!.Value, 1);
         var dayBefore = PreviousMonthDays(date);
         var dateToSet = date.GetFirstDayOfMonth().AddDays(-dayBefore);
         for (var i = 7; i < children.Count; i++)
@@ -412,12 +411,12 @@ public class CalendarView : TemplatedControl
         return i == 0 ? DateTimeHelper.NumberOfDaysPerWeek : i;
     }
 
-    private void OnCellDatePreviewed(object sender, CalendarDayButtonEventArgs e)
+    private void OnCellDatePreviewed(object? sender, CalendarDayButtonEventArgs e)
     {
         DatePreviewed?.Invoke(this, e);
     }
 
-    private void OnCellDateSelected(object sender, CalendarDayButtonEventArgs e)
+    private void OnCellDateSelected(object? sender, CalendarDayButtonEventArgs e)
     {
         if (e.Date.HasValue && e.Date.Value.Month != ContextDate.Month)
         {
@@ -432,7 +431,7 @@ public class CalendarView : TemplatedControl
     /// </summary>
     /// <param name="sender"></param>
     /// <param name="e"></param>
-    private void OnHeaderMonthButtonClick(object sender, RoutedEventArgs e)
+    private void OnHeaderMonthButtonClick(object? sender, RoutedEventArgs e)
     {
         SetCurrentValue(ModeProperty, CalendarViewMode.Year);
         UpdateYearButtons();
@@ -443,7 +442,7 @@ public class CalendarView : TemplatedControl
     /// </summary>
     /// <param name="sender"></param>
     /// <param name="e"></param>
-    private void OnHeaderYearButtonClick(object sender, RoutedEventArgs e)
+    private void OnHeaderYearButtonClick(object? sender, RoutedEventArgs e)
     {
         if (_yearGrid is null) return;
         SetCurrentValue(ModeProperty, CalendarViewMode.Decade);
@@ -464,10 +463,9 @@ public class CalendarView : TemplatedControl
     /// </summary>
     /// <param name="sender"></param>
     /// <param name="e"></param>
-    private void OnYearItemSelected(object sender, CalendarYearButtonEventArgs e)
+    private void OnYearItemSelected(object? sender, CalendarYearButtonEventArgs e)
     {
         if (_yearGrid is null) return;
-        var buttons = _yearGrid.Children.OfType<CalendarYearButton>().ToList();
         if (Mode == CalendarViewMode.Century)
         {
             Mode = CalendarViewMode.Decade;
@@ -481,7 +479,7 @@ public class CalendarView : TemplatedControl
         else if (Mode == CalendarViewMode.Year)
         {
             Mode = CalendarViewMode.Month;
-            ContextDate = ContextDate.With(null, e.Context.Month, null, null);
+            ContextDate = ContextDate.With(null, e.Context.Month);
             UpdateDayButtons();
         }
         else if (Mode == CalendarViewMode.Month)
@@ -600,7 +598,7 @@ public class CalendarView : TemplatedControl
         DatePreviewed?.Invoke(this, new CalendarDayButtonEventArgs(null));
     }
 
-    private bool _dateContextSyncing = false;
+    private bool _dateContextSyncing;
     /// <summary>
     /// Used for syncing the context date for DateRangePicker. mark a flag to avoid infinitely loop. 
     /// </summary>
diff --git a/src/Ursa/Controls/DateTimePicker/CalendarYearButton.cs b/src/Ursa/Controls/DateTimePicker/CalendarYearButton.cs
index 0ed4282..37428ad 100644
--- a/src/Ursa/Controls/DateTimePicker/CalendarYearButton.cs
+++ b/src/Ursa/Controls/DateTimePicker/CalendarYearButton.cs
@@ -1,4 +1,3 @@
-using System.Diagnostics;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Mixins;
diff --git a/src/Ursa/Controls/DateTimePicker/DatePicker.cs b/src/Ursa/Controls/DateTimePicker/DatePicker.cs
index b70c152..a239cc2 100644
--- a/src/Ursa/Controls/DateTimePicker/DatePicker.cs
+++ b/src/Ursa/Controls/DateTimePicker/DatePicker.cs
@@ -23,7 +23,6 @@ public class DatePicker: DatePickerBase, IClearControl
     public const string PART_TextBox = "PART_TextBox";
     public const string PART_Calendar = "PART_Calendar";
     private Button? _button;
-    private Popup? _popup;
     private TextBox? _textBox;
     private CalendarView? _calendar;
 
@@ -79,7 +78,7 @@ public class DatePicker: DatePickerBase, IClearControl
         }
         
         _button = e.NameScope.Find<Button>(PART_Button);
-        _popup = e.NameScope.Find<Popup>(PART_Popup);
+        e.NameScope.Find<Popup>(PART_Popup);
         _textBox = e.NameScope.Find<TextBox>(PART_TextBox);
         _calendar = e.NameScope.Find<CalendarView>(PART_Calendar);
         
@@ -94,19 +93,19 @@ public class DatePicker: DatePickerBase, IClearControl
         }
     }
 
-    private void OnDateSelected(object sender, CalendarDayButtonEventArgs e)
+    private void OnDateSelected(object? sender, CalendarDayButtonEventArgs e)
     {
         SetCurrentValue(SelectedDateProperty, e.Date);
         SetCurrentValue(IsDropdownOpenProperty, false);
     }
 
-    private void OnButtonClick(object sender, RoutedEventArgs e)
+    private void OnButtonClick(object? sender, RoutedEventArgs e)
     {
         Focus(NavigationMethod.Pointer);
         SetCurrentValue(IsDropdownOpenProperty, !IsDropdownOpen);
     }
 
-    private void OnTextBoxPointerPressed(object sender, PointerPressedEventArgs e)
+    private void OnTextBoxPointerPressed(object? sender, PointerPressedEventArgs e)
     {
         if (_calendar is not null)
         {
@@ -118,7 +117,7 @@ public class DatePicker: DatePickerBase, IClearControl
     }
     
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private void OnTextChanged(object sender, TextChangedEventArgs e)
+    private void OnTextChanged(object? sender, TextChangedEventArgs e)
     {
         SetSelectedDate(true);
     }
@@ -146,7 +145,6 @@ public class DatePicker: DatePickerBase, IClearControl
                 SetCurrentValue(SelectedDateProperty, date);
                 if (_calendar is not null)
                 {
-                    var d = SelectedDate ?? DateTime.Today;
                     _calendar.ContextDate = _calendar.ContextDate.With(year: date.Year, month: date.Month);
                     _calendar.UpdateDayButtons();
                 }
@@ -164,7 +162,7 @@ public class DatePicker: DatePickerBase, IClearControl
         }
     }
 
-    private void OnTextBoxGetFocus(object sender, GotFocusEventArgs e)
+    private void OnTextBoxGetFocus(object? sender, GotFocusEventArgs e)
     {
         if (_calendar is not null)
         {
diff --git a/src/Ursa/Controls/DateTimePicker/DateRangePicker.cs b/src/Ursa/Controls/DateTimePicker/DateRangePicker.cs
index bbc43df..f6b7ad5 100644
--- a/src/Ursa/Controls/DateTimePicker/DateRangePicker.cs
+++ b/src/Ursa/Controls/DateTimePicker/DateRangePicker.cs
@@ -43,7 +43,6 @@ public class DateRangePicker : DatePickerBase, IClearControl
     private Button? _button;
     private CalendarView? _endCalendar;
     private TextBox? _endTextBox;
-    private Popup? _popup;
     private DateTime? _previewEnd;
 
     private DateTime? _previewStart;
@@ -140,7 +139,7 @@ public class DateRangePicker : DatePickerBase, IClearControl
         }
 
         _button = e.NameScope.Find<Button>(PART_Button);
-        _popup = e.NameScope.Find<Popup>(PART_Popup);
+        e.NameScope.Find<Popup>(PART_Popup);
         _startCalendar = e.NameScope.Find<CalendarView>(PART_StartCalendar);
         _endCalendar = e.NameScope.Find<CalendarView>(PART_EndCalendar);
         _startTextBox = e.NameScope.Find<TextBox>(PART_StartTextBox);
@@ -168,28 +167,28 @@ public class DateRangePicker : DatePickerBase, IClearControl
         }
     }
 
-    private void OnTextBoxLostFocus(object sender, RoutedEventArgs e)
+    private void OnTextBoxLostFocus(object? sender, RoutedEventArgs e)
     {
-        if (sender == _startTextBox)
+        if (Equals(sender, _startTextBox))
             OnTextChangedInternal(_startTextBox, SelectedStartDateProperty);
-        else if (sender == _endTextBox) OnTextChangedInternal(_endTextBox, SelectedEndDateProperty);
+        else if (Equals(sender, _endTextBox)) OnTextChangedInternal(_endTextBox, SelectedEndDateProperty);
     }
 
-    private void OnContextDateChanged(object sender, CalendarContext e)
+    private void OnContextDateChanged(object? sender, CalendarContext e)
     {
-        if (sender == _startCalendar && _startCalendar?.Mode == CalendarViewMode.Month)
+        if (Equals(sender, _startCalendar) && _startCalendar?.Mode == CalendarViewMode.Month)
         {
             var needsUpdate = EnableMonthSync || _startCalendar?.ContextDate.CompareTo(_endCalendar?.ContextDate) >= 0;
             if (needsUpdate) _endCalendar?.SyncContextDate(_startCalendar?.ContextDate.NextMonth());
         }
-        else if (sender == _endCalendar && _endCalendar?.Mode == CalendarViewMode.Month)
+        else if (Equals(sender, _endCalendar) && _endCalendar?.Mode == CalendarViewMode.Month)
         {
             var needsUpdate = EnableMonthSync || _endCalendar?.ContextDate.CompareTo(_startCalendar?.ContextDate) <= 0;
             if (needsUpdate) _startCalendar?.SyncContextDate(_endCalendar?.ContextDate.PreviousMonth());
         }
     }
 
-    private void OnDatePreviewed(object sender, CalendarDayButtonEventArgs e)
+    private void OnDatePreviewed(object? sender, CalendarDayButtonEventArgs e)
     {
         if (_start == true)
         {
@@ -205,7 +204,7 @@ public class DateRangePicker : DatePickerBase, IClearControl
         }
     }
 
-    private void OnDateSelected(object sender, CalendarDayButtonEventArgs e)
+    private void OnDateSelected(object? sender, CalendarDayButtonEventArgs e)
     {
         if (_start == true)
         {
@@ -241,16 +240,16 @@ public class DateRangePicker : DatePickerBase, IClearControl
         }
     }
 
-    private void OnButtonClick(object sender, RoutedEventArgs e)
+    private void OnButtonClick(object? sender, RoutedEventArgs e)
     {
         Focus(NavigationMethod.Pointer);
         SetCurrentValue(IsDropdownOpenProperty, !IsDropdownOpen);
         _start = true;
     }
 
-    private void OnTextBoxPointerPressed(object sender, PointerPressedEventArgs e)
+    private void OnTextBoxPointerPressed(object? sender, PointerPressedEventArgs e)
     {
-        if (sender == _startTextBox)
+        if (Equals(sender, _startTextBox))
         {
             _start = true;
             if (_startCalendar is not null)
@@ -270,11 +269,11 @@ public class DateRangePicker : DatePickerBase, IClearControl
                     date2 = date2.Value.AddMonths(1);
                 }
 
-                _endCalendar.ContextDate = new CalendarContext(date2?.Year, date2?.Month);
+                _endCalendar.ContextDate = new CalendarContext(date2.Value.Year, date2.Value.Month);
                 _endCalendar.UpdateDayButtons();
             }
         }
-        else if (sender == _endTextBox)
+        else if (Equals(sender, _endTextBox))
         {
             _start = false;
             if (_endCalendar is not null)
@@ -294,7 +293,7 @@ public class DateRangePicker : DatePickerBase, IClearControl
                     date2 = date2.Value.AddMonths(-1);
                 }
 
-                _startCalendar.ContextDate = new CalendarContext(date2?.Year, date2?.Month);
+                _startCalendar.ContextDate = new CalendarContext(date2.Value.Year, date2.Value.Month);
                 _startCalendar.UpdateDayButtons();
             }
         }
@@ -302,11 +301,11 @@ public class DateRangePicker : DatePickerBase, IClearControl
         SetCurrentValue(IsDropdownOpenProperty, true);
     }
 
-    private void OnTextChanged(object sender, TextChangedEventArgs e)
+    private void OnTextChanged(object? sender, TextChangedEventArgs e)
     {
-        if (sender == _startTextBox)
+        if (Equals(sender, _startTextBox))
             OnTextChangedInternal(_startTextBox, SelectedStartDateProperty, true);
-        else if (sender == _endTextBox) OnTextChangedInternal(_endTextBox, SelectedEndDateProperty, true);
+        else if (Equals(sender, _endTextBox)) OnTextChangedInternal(_endTextBox, SelectedEndDateProperty, true);
     }
 
     private void OnTextChangedInternal(TextBox? textBox, AvaloniaProperty property, bool fromText = false)
@@ -314,12 +313,12 @@ public class DateRangePicker : DatePickerBase, IClearControl
         if (string.IsNullOrEmpty(textBox?.Text))
         {
             SetCurrentValue(property, null);
-            _startCalendar?.ClearSelection(true);
+            _startCalendar?.ClearSelection();
             _endCalendar?.ClearSelection(end: true);
         }
         else if (DisplayFormat is null || DisplayFormat.Length == 0)
         {
-            if (DateTime.TryParse(textBox?.Text, out var defaultTime))
+            if (DateTime.TryParse(textBox.Text, out var defaultTime))
             {
                 SetCurrentValue(property, defaultTime);
                 _startCalendar?.MarkDates(defaultTime, defaultTime);
@@ -328,7 +327,7 @@ public class DateRangePicker : DatePickerBase, IClearControl
         }
         else
         {
-            if (DateTime.TryParseExact(textBox?.Text, DisplayFormat, CultureInfo.CurrentUICulture, DateTimeStyles.None,
+            if (DateTime.TryParseExact(textBox.Text, DisplayFormat, CultureInfo.CurrentUICulture, DateTimeStyles.None,
                     out var date))
             {
                 SetCurrentValue(property, date);
@@ -356,19 +355,18 @@ public class DateRangePicker : DatePickerBase, IClearControl
                 if (!fromText)
                 {
                     SetCurrentValue(property, null);
-                    textBox?.SetValue(TextBox.TextProperty, null);
-                    _startCalendar?.ClearSelection(true);
+                    textBox.SetValue(TextBox.TextProperty, null);
+                    _startCalendar?.ClearSelection();
                     _endCalendar?.ClearSelection(end: true);
                 }
             }
         }
     }
 
-    private void OnTextBoxGetFocus(object sender, GotFocusEventArgs e)
+    private void OnTextBoxGetFocus(object? sender, GotFocusEventArgs e)
     {
         if (_startCalendar is not null && _startCalendar?.Mode == CalendarViewMode.Month)
         {
-            var date = SelectedStartDate ?? DateTime.Today;
             //_startCalendar.ContextDate = new CalendarContext(date.Year, date.Month);
             //_startCalendar.UpdateDayButtons();
         }
diff --git a/src/Ursa/Controls/DateTimePicker/DateTimeHelper.cs b/src/Ursa/Controls/DateTimePicker/DateTimeHelper.cs
index 4fbe89f..06d9ee2 100644
--- a/src/Ursa/Controls/DateTimePicker/DateTimeHelper.cs
+++ b/src/Ursa/Controls/DateTimePicker/DateTimeHelper.cs
@@ -10,7 +10,7 @@ internal static class DateTimeHelper
     public static DateTimeFormatInfo GetCurrentDateTimeFormatInfo()
     {
         if (CultureInfo.CurrentCulture.Calendar is GregorianCalendar) return CultureInfo.CurrentCulture.DateTimeFormat;
-        System.Globalization.Calendar? calendar =
+        Calendar? calendar =
             CultureInfo.CurrentCulture.OptionalCalendars.OfType<GregorianCalendar>().FirstOrDefault();
         string cultureName = calendar is null ? CultureInfo.InvariantCulture.Name : CultureInfo.CurrentCulture.Name;
         var dt = new CultureInfo(cultureName).DateTimeFormat;
diff --git a/src/Ursa/Controls/DateTimePicker/TimePicker.cs b/src/Ursa/Controls/DateTimePicker/TimePicker.cs
index 1383bac..73db3b8 100644
--- a/src/Ursa/Controls/DateTimePicker/TimePicker.cs
+++ b/src/Ursa/Controls/DateTimePicker/TimePicker.cs
@@ -30,7 +30,6 @@ public class TimePicker : TimePickerBase, IClearControl
         nameof(Watermark));
 
     private Button? _button;
-    private Popup? _popup;
     private TimePickerPresenter? _presenter;
     private TextBox? _textBox;
 
@@ -42,10 +41,11 @@ public class TimePicker : TimePickerBase, IClearControl
         DisplayFormatProperty.Changed.AddClassHandler<TimePicker, string?>((picker, args) => picker.OnDisplayFormatChanged(args));
     }
 
-    private void OnDisplayFormatChanged(AvaloniaPropertyChangedEventArgs<string?> args)
+    private void OnDisplayFormatChanged(AvaloniaPropertyChangedEventArgs<string?> _)
     {
         if (_textBox is null) return;
         var time = SelectedTime;
+        if (time is null) return;
         var date = new DateTime( 1, 1, 1, time.Value.Hours, time.Value.Minutes, time.Value.Seconds);
         var text = date.ToString(DisplayFormat);
         _textBox.Text = text;
@@ -79,7 +79,7 @@ public class TimePicker : TimePickerBase, IClearControl
         Button.ClickEvent.RemoveHandler(OnButtonClick, _button);
 
         _textBox = e.NameScope.Find<TextBox>(PART_TextBox);
-        _popup = e.NameScope.Find<Popup>(PartNames.PART_Popup);
+        e.NameScope.Find<Popup>(PartNames.PART_Popup);
         _presenter = e.NameScope.Find<TimePickerPresenter>(PART_Presenter);
         _button = e.NameScope.Find<Button>(PART_Button);
 
diff --git a/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs b/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs
index 044c2f6..a3bd900 100644
--- a/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs
+++ b/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs
@@ -69,7 +69,7 @@ public class TimePickerPresenter : TemplatedControl
     private DateTimePickerPanel? _secondSelector;
     private Control? _secondSeparator;
     private Control? _thirdSeparator;
-    internal TimeSpan _timeHolder;
+    internal TimeSpan TimeHolder;
     private bool _updateFromTimeChange;
     private bool _use12Clock;
 
@@ -172,7 +172,7 @@ public class TimePickerPresenter : TemplatedControl
             }
             catch
             {
-                
+                // ignored
             }
         }
 
@@ -224,11 +224,11 @@ public class TimePickerPresenter : TemplatedControl
         UpdatePanelsFromSelectedTime(Time);
     }
 
-    private void OnPanelSelectionChanged(object sender, System.EventArgs e)
+    private void OnPanelSelectionChanged(object? sender, System.EventArgs e)
     {
         if (_updateFromTimeChange) return;
-        if (!_use12Clock && sender == _ampmSelector) return;
-        var time = NeedsConfirmation ? _timeHolder : Time ?? DateTime.Now.TimeOfDay;
+        if (!_use12Clock && Equals(sender, _ampmSelector)) return;
+        var time = NeedsConfirmation ? TimeHolder : Time ?? DateTime.Now.TimeOfDay;
         var hour = _hourSelector?.SelectedValue ?? time.Hours;
         var minute = _minuteSelector?.SelectedValue ?? time.Minutes;
         var second = _secondSelector?.SelectedValue ?? time.Seconds;
@@ -251,7 +251,7 @@ public class TimePickerPresenter : TemplatedControl
         }
         var newTime = new TimeSpan(hour, minute, second);
         if (NeedsConfirmation)
-            _timeHolder = newTime;
+            TimeHolder = newTime;
         else
             SetCurrentValue(TimeProperty, newTime);
     }
@@ -314,7 +314,7 @@ public class TimePickerPresenter : TemplatedControl
 
     public void Confirm()
     {
-        if (NeedsConfirmation) SetCurrentValue(TimeProperty, _timeHolder);
+        if (NeedsConfirmation) SetCurrentValue(TimeProperty, TimeHolder);
     }
 
     private void SetIfChanged(DateTimePickerPanel? panel, int index)
diff --git a/src/Ursa/Controls/DateTimePicker/TimeRangePicker.cs b/src/Ursa/Controls/DateTimePicker/TimeRangePicker.cs
index 6bdf450..62ab178 100644
--- a/src/Ursa/Controls/DateTimePicker/TimeRangePicker.cs
+++ b/src/Ursa/Controls/DateTimePicker/TimeRangePicker.cs
@@ -45,7 +45,6 @@ public class TimeRangePicker : TimePickerBase, IClearControl
     private Button? _button;
     private TimePickerPresenter? _endPresenter;
     private TextBox? _endTextBox;
-    private Popup? _popup;
     private TimePickerPresenter? _startPresenter;
 
     private TextBox? _startTextBox;
@@ -114,7 +113,7 @@ public class TimeRangePicker : TimePickerBase, IClearControl
         PointerPressedEvent.RemoveHandler(OnTextBoxPointerPressed, _startTextBox, _endTextBox);
         Button.ClickEvent.RemoveHandler(OnButtonClick, _button);
 
-        _popup = e.NameScope.Find<Popup>(PartNames.PART_Popup);
+        e.NameScope.Find<Popup>(PartNames.PART_Popup);
         _startTextBox = e.NameScope.Find<TextBox>(PART_StartTextBox);
         _endTextBox = e.NameScope.Find<TextBox>(PART_EndTextBox);
         _startPresenter = e.NameScope.Find<TimePickerPresenter>(PART_StartPresenter);
@@ -127,18 +126,18 @@ public class TimeRangePicker : TimePickerBase, IClearControl
         Button.ClickEvent.AddHandler(OnButtonClick, _button);
     }
 
-    private void OnButtonClick(object sender, RoutedEventArgs e)
+    private void OnButtonClick(object? sender, RoutedEventArgs e)
     {
         Focus(NavigationMethod.Pointer);
         SetCurrentValue(IsDropdownOpenProperty, !IsDropdownOpen);
     }
 
-    private void OnTextBoxPointerPressed(object sender, PointerPressedEventArgs e)
+    private void OnTextBoxPointerPressed(object? sender, PointerPressedEventArgs e)
     {
         SetCurrentValue(IsDropdownOpenProperty, true);
     }
 
-    private void OnTextBoxGetFocus(object sender, GotFocusEventArgs e)
+    private void OnTextBoxGetFocus(object? sender, GotFocusEventArgs e)
     {
         SetCurrentValue(IsDropdownOpenProperty, true);
     }
@@ -161,7 +160,7 @@ public class TimeRangePicker : TimePickerBase, IClearControl
 
         if (e.Key == Key.Tab)
         {
-            if (e.Source == _endTextBox) SetCurrentValue(IsDropdownOpenProperty, false);
+            if (Equals(e.Source, _endTextBox)) SetCurrentValue(IsDropdownOpenProperty, false);
             return;
         }
 
diff --git a/src/Ursa/Controls/DateTimePicker/UrsaDateTimeScrollPanel.cs b/src/Ursa/Controls/DateTimePicker/UrsaDateTimeScrollPanel.cs
index 4915bd3..1411a4e 100644
--- a/src/Ursa/Controls/DateTimePicker/UrsaDateTimeScrollPanel.cs
+++ b/src/Ursa/Controls/DateTimePicker/UrsaDateTimeScrollPanel.cs
@@ -1,11 +1,5 @@
 using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
-using Avalonia.Input;
-using Avalonia.Interactivity;
-using Avalonia.Layout;
-using Avalonia.VisualTree;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/Dialog/CustomDialogControl.cs b/src/Ursa/Controls/Dialog/CustomDialogControl.cs
index 9149106..d2145c9 100644
--- a/src/Ursa/Controls/Dialog/CustomDialogControl.cs
+++ b/src/Ursa/Controls/Dialog/CustomDialogControl.cs
@@ -1,15 +1,5 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Controls.Metadata;
-using Avalonia.Controls.Primitives;
-using Avalonia.Input;
-using Avalonia.Input.GestureRecognizers;
-using Avalonia.Interactivity;
-using Avalonia.Threading;
+using Avalonia.Controls.Primitives;
 using Irihi.Avalonia.Shared.Contracts;
-using Ursa.Common;
-using Ursa.Controls.OverlayShared;
-using Ursa.EventArgs;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/Dialog/DefaultDialogControl.cs b/src/Ursa/Controls/Dialog/DefaultDialogControl.cs
index ffa8c77..5f0c685 100644
--- a/src/Ursa/Controls/Dialog/DefaultDialogControl.cs
+++ b/src/Ursa/Controls/Dialog/DefaultDialogControl.cs
@@ -2,12 +2,9 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
-using Avalonia.Input;
 using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Contracts;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
-using Ursa.EventArgs;
 
 namespace Ursa.Controls;
 
@@ -95,7 +92,7 @@ public class DefaultDialogControl: DialogControlBase
         }
     }
     
-    private void DefaultButtonsClose(object sender, RoutedEventArgs args)
+    private void DefaultButtonsClose(object? sender, RoutedEventArgs args)
     {
         if (sender is Button button)
         {
diff --git a/src/Ursa/Controls/Dialog/DefaultDialogWindow.cs b/src/Ursa/Controls/Dialog/DefaultDialogWindow.cs
index 46d7bc9..67ed3ff 100644
--- a/src/Ursa/Controls/Dialog/DefaultDialogWindow.cs
+++ b/src/Ursa/Controls/Dialog/DefaultDialogWindow.cs
@@ -5,7 +5,6 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Contracts;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
 
 namespace Ursa.Controls;
 
@@ -57,27 +56,26 @@ public class DefaultDialogWindow: DialogWindow
         SetButtonVisibility();
     }
 
-    private void OnDefaultClose(object sender, RoutedEventArgs e)
+    private void OnDefaultClose(object? sender, RoutedEventArgs e)
     {
-        if (sender == _yesButton)
+        if (Equals(sender, _yesButton))
         {
             Close(DialogResult.Yes);
             return;
         }
-        if(sender == _noButton)
+        if(Equals(sender, _noButton))
         {
             Close(DialogResult.No);
             return;
         }
-        if(sender == _okButton)
+        if(Equals(sender, _okButton))
         {
             Close(DialogResult.OK);
             return;
         }
-        if(sender == _cancelButton)
+        if(Equals(sender, _cancelButton))
         {
             Close(DialogResult.Cancel);
-            return;
         }
     }
 
@@ -125,7 +123,7 @@ public class DefaultDialogWindow: DialogWindow
         if (button is not null) button.IsVisible = visible;
     }
 
-    protected internal override void OnCloseButtonClicked(object sender, RoutedEventArgs args)
+    protected override void OnCloseButtonClicked(object? sender, RoutedEventArgs args)
     {
         if (DataContext is IDialogContext context)
         {
diff --git a/src/Ursa/Controls/Dialog/DialogControlBase.cs b/src/Ursa/Controls/Dialog/DialogControlBase.cs
index e057f9c..1e3e2fd 100644
--- a/src/Ursa/Controls/Dialog/DialogControlBase.cs
+++ b/src/Ursa/Controls/Dialog/DialogControlBase.cs
@@ -6,9 +6,7 @@ using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.LogicalTree;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
 using Ursa.Controls.OverlayShared;
-using Ursa.EventArgs;
 
 namespace Ursa.Controls;
 
@@ -190,7 +188,7 @@ public abstract class DialogControlBase : OverlayFeedbackElement
         e.Source = this;
     }
 
-    private void OnCloseButtonClick(object sender, RoutedEventArgs args) => Close();
+    private void OnCloseButtonClick(object? sender, RoutedEventArgs args) => Close();
 
     internal void SetAsModal(bool modal)
     {
diff --git a/src/Ursa/Controls/Dialog/DialogWindow.cs b/src/Ursa/Controls/Dialog/DialogWindow.cs
index f183263..fabf85b 100644
--- a/src/Ursa/Controls/Dialog/DialogWindow.cs
+++ b/src/Ursa/Controls/Dialog/DialogWindow.cs
@@ -6,7 +6,6 @@ using Avalonia.Input;
 using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Contracts;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
 
 namespace Ursa.Controls;
 
@@ -59,7 +58,7 @@ public class DialogWindow: Window
         Close(args);
     }
 
-    protected internal virtual void OnCloseButtonClicked(object sender, RoutedEventArgs args)
+    protected virtual void OnCloseButtonClicked(object? sender, RoutedEventArgs args)
     {
         if (DataContext is IDialogContext context)
         {
@@ -71,7 +70,7 @@ public class DialogWindow: Window
         }
     }
     
-    private void OnTitlePointerPressed(object sender, PointerPressedEventArgs e)
+    private void OnTitlePointerPressed(object? sender, PointerPressedEventArgs e)
     {
         this.BeginMoveDrag(e);
     }
diff --git a/src/Ursa/Controls/Dialog/OverlayDialog.cs b/src/Ursa/Controls/Dialog/OverlayDialog.cs
index 38cd91a..1170044 100644
--- a/src/Ursa/Controls/Dialog/OverlayDialog.cs
+++ b/src/Ursa/Controls/Dialog/OverlayDialog.cs
@@ -1,7 +1,6 @@
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Layout;
-using Ursa.Common;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/DisableContainer/DisableContainer.cs b/src/Ursa/Controls/DisableContainer/DisableContainer.cs
index f005c41..a311313 100644
--- a/src/Ursa/Controls/DisableContainer/DisableContainer.cs
+++ b/src/Ursa/Controls/DisableContainer/DisableContainer.cs
@@ -1,5 +1,4 @@
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Metadata;
diff --git a/src/Ursa/Controls/Drawer/DefaultDrawerControl.cs b/src/Ursa/Controls/Drawer/DefaultDrawerControl.cs
index 9a2feb1..baac81a 100644
--- a/src/Ursa/Controls/Drawer/DefaultDrawerControl.cs
+++ b/src/Ursa/Controls/Drawer/DefaultDrawerControl.cs
@@ -5,7 +5,6 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Contracts;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
 using Ursa.EventArgs;
 
 namespace Ursa.Controls;
diff --git a/src/Ursa/Controls/Drawer/DrawerControlBase.cs b/src/Ursa/Controls/Drawer/DrawerControlBase.cs
index e8c20f7..45468ca 100644
--- a/src/Ursa/Controls/Drawer/DrawerControlBase.cs
+++ b/src/Ursa/Controls/Drawer/DrawerControlBase.cs
@@ -3,7 +3,6 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
-using Avalonia.Threading;
 using Irihi.Avalonia.Shared.Contracts;
 using Irihi.Avalonia.Shared.Helpers;
 using Ursa.Common;
@@ -75,12 +74,12 @@ public abstract class DrawerControlBase: OverlayFeedbackElement
         }
     }
 
-    private void OnContextRequestClose(object sender, object? e)
+    private void OnContextRequestClose(object? sender, object? e)
     {
         RaiseEvent(new ResultEventArgs(ClosedEvent, e));
     }
 
-    private void OnCloseButtonClick(object sender, RoutedEventArgs e) => Close();
+    private void OnCloseButtonClick(object? sender, RoutedEventArgs e) => Close();
 
     public override void Close()
     {
diff --git a/src/Ursa/Controls/DualBadge.cs b/src/Ursa/Controls/DualBadge.cs
index 7ffd789..89563c2 100644
--- a/src/Ursa/Controls/DualBadge.cs
+++ b/src/Ursa/Controls/DualBadge.cs
@@ -66,9 +66,9 @@ public class DualBadge : HeaderedContentControl
 
     static DualBadge()
     {
-        IconProperty.Changed.AddClassHandler<DualBadge>((o, args) => o.OnIconChanged());
-        HeaderProperty.Changed.AddClassHandler<DualBadge>((o, args) => o.OnHeaderChanged());
-        ContentProperty.Changed.AddClassHandler<DualBadge>((o, args) => o.OnContentChanged());
+        IconProperty.Changed.AddClassHandler<DualBadge>((o, _) => o.OnIconChanged());
+        HeaderProperty.Changed.AddClassHandler<DualBadge>((o, _) => o.OnHeaderChanged());
+        ContentProperty.Changed.AddClassHandler<DualBadge>((o, _) => o.OnContentChanged());
     }
 
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
diff --git a/src/Ursa/Controls/EnumSelector/EnumSelector.cs b/src/Ursa/Controls/EnumSelector/EnumSelector.cs
index 74bf029..ed73364 100644
--- a/src/Ursa/Controls/EnumSelector/EnumSelector.cs
+++ b/src/Ursa/Controls/EnumSelector/EnumSelector.cs
@@ -1,6 +1,5 @@
 using System.ComponentModel;
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.Data;
 
@@ -136,12 +135,12 @@ public class EnumSelector: TemplatedControl
         if (EnumType is null) return new List<EnumItemTuple>();
         var values = Enum.GetValues(EnumType);
         List<EnumItemTuple> list = new();
-        var fields = EnumType.GetFields();
         foreach (var value in values)
         {
             if (value.GetType() == EnumType)
             {
                 var displayName = value.ToString();
+                if(displayName is null) continue;
                 var field = EnumType.GetField(displayName);
                 var description = field?.GetCustomAttributes(typeof(DescriptionAttribute), false).FirstOrDefault();
                 if (description is not null)
diff --git a/src/Ursa/Controls/Form/FormGroup.cs b/src/Ursa/Controls/Form/FormGroup.cs
index 875e3ec..42803f9 100644
--- a/src/Ursa/Controls/Form/FormGroup.cs
+++ b/src/Ursa/Controls/Form/FormGroup.cs
@@ -1,5 +1,4 @@
-using Avalonia;
-using Avalonia.Controls;
+using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 
 namespace Ursa.Controls;
diff --git a/src/Ursa/Controls/Form/FormItem.cs b/src/Ursa/Controls/Form/FormItem.cs
index e33d682..9157f06 100644
--- a/src/Ursa/Controls/Form/FormItem.cs
+++ b/src/Ursa/Controls/Form/FormItem.cs
@@ -1,7 +1,6 @@
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
-using Avalonia.Controls.Primitives;
 using Avalonia.Layout;
 using Avalonia.Reactive;
 using Avalonia.VisualTree;
diff --git a/src/Ursa/Controls/IPv4Box.cs b/src/Ursa/Controls/IPv4Box.cs
index f0c0acd..e88dc29 100644
--- a/src/Ursa/Controls/IPv4Box.cs
+++ b/src/Ursa/Controls/IPv4Box.cs
@@ -1,4 +1,3 @@
-using System.Diagnostics;
 using System.Net;
 using Avalonia;
 using Avalonia.Controls;
@@ -150,8 +149,11 @@ public class IPv4Box: TemplatedControl
         }
         if (keymap is not null && Match(keymap.SelectAll))
         {
-            _currentActivePresenter.SelectionStart = 0;
-            _currentActivePresenter.SelectionEnd = _currentActivePresenter.Text?.Length ?? 0;
+            if (_currentActivePresenter is not null)
+            {
+                _currentActivePresenter.SelectionStart = 0;
+                _currentActivePresenter.SelectionEnd = _currentActivePresenter.Text?.Length ?? 0;
+            }
             e.Handled = true;
             return;
         }
@@ -217,7 +219,7 @@ public class IPv4Box: TemplatedControl
     protected override void OnTextInput(TextInputEventArgs e)
     {
         if (e.Handled) return;
-        string? s = e.Text;
+        var s = e.Text;
         if (string.IsNullOrEmpty(s)) return;
         if (s == ".")
         {
@@ -231,10 +233,10 @@ public class IPv4Box: TemplatedControl
             e.Handled = false;
             return;
         }
-        if (!char.IsNumber(s![0])) return;
+        if (!char.IsNumber(s[0])) return;
         if (_currentActivePresenter != null)
         {
-            int index = Math.Min(_currentActivePresenter.CaretIndex, _currentActivePresenter.Text.Length);
+            int index = Math.Min(_currentActivePresenter.CaretIndex, _currentActivePresenter.Text?.Length ?? 0);
             string? oldText = _currentActivePresenter.Text;
             if (oldText is null)
             {
@@ -245,11 +247,11 @@ public class IPv4Box: TemplatedControl
             {
                 _currentActivePresenter.DeleteSelection();
                 _currentActivePresenter.ClearSelection();
-                oldText = _currentActivePresenter.Text;
+                oldText = _currentActivePresenter.Text??string.Empty;
 
-                string newText = string.IsNullOrEmpty(oldText)
+                var newText = string.IsNullOrEmpty(oldText)
                     ? s
-                    : oldText?.Substring(0, index) + s + oldText?.Substring(Math.Min(index, oldText.Length));
+                    : oldText.Substring(0, index) + s + oldText.Substring(Math.Min(index, oldText.Length));
                 if (newText.Length > 3)
                 {
                     newText = newText.Substring(0, 3);
@@ -463,7 +465,7 @@ public class IPv4Box: TemplatedControl
         else
         {
             int index = presenter.CaretIndex;
-            string newText = oldText?.Substring(0, index - 1) + oldText?.Substring(Math.Min(index, oldText.Length));
+            string newText = oldText.Substring(0, index - 1) + oldText.Substring(Math.Min(index, oldText.Length));
             presenter.MoveCaretHorizontal(LogicalDirection.Backward);
             presenter.Text = newText;
         }
@@ -529,7 +531,8 @@ public class IPv4Box: TemplatedControl
     {
         string s = string.Join(".", _firstText?.Text, _secondText?.Text, _thirdText?.Text, _fourthText?.Text);
         IClipboard? clipboard = TopLevel.GetTopLevel(this)?.Clipboard;
-        clipboard?.SetTextAsync(s);
+        if (clipboard is null) return;
+        await clipboard.SetTextAsync(s);
     }
     
     public static KeyGesture? CopyKeyGesture { get; } = Application.Current?.PlatformSettings?.HotkeyConfiguration.Copy.FirstOrDefault();
@@ -540,7 +543,7 @@ public class IPv4Box: TemplatedControl
     {
         IClipboard? clipboard = TopLevel.GetTopLevel(this)?.Clipboard;
         if (clipboard is null) return;
-        string s = await clipboard.GetTextAsync();
+        var s = await clipboard.GetTextAsync();
         if (IPAddress.TryParse(s, out var address))
         {
             IPAddress = address;
diff --git a/src/Ursa/Controls/Icons/TwoTonePathIcon.cs b/src/Ursa/Controls/Icons/TwoTonePathIcon.cs
index 8fdc681..a6bc83e 100644
--- a/src/Ursa/Controls/Icons/TwoTonePathIcon.cs
+++ b/src/Ursa/Controls/Icons/TwoTonePathIcon.cs
@@ -1,5 +1,4 @@
-using System.ComponentModel;
-using Avalonia;
+using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
diff --git a/src/Ursa/Controls/ImageViewer/ImageViewer.cs b/src/Ursa/Controls/ImageViewer/ImageViewer.cs
index 93de67c..e0abde2 100644
--- a/src/Ursa/Controls/ImageViewer/ImageViewer.cs
+++ b/src/Ursa/Controls/ImageViewer/ImageViewer.cs
@@ -5,7 +5,6 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Media;
-using Avalonia.Media.Imaging;
 
 namespace Ursa.Controls;
 
@@ -18,8 +17,7 @@ public class ImageViewer: TemplatedControl
     public const string PART_Layer = "PART_Layer";
     public const string PC_Moving = ":moving";
     
-    private Image? _image = null!;
-    private VisualLayerManager? _layer;
+    private Image? _image;
     private Point? _lastClickPoint;
     private Point? _lastLocation;
     private bool _moving;
@@ -128,28 +126,14 @@ public class ImageViewer: TemplatedControl
     {
         if (_moving) return;
         var newValue = args.GetNewValue<double>();
-        if (_lastLocation is not null)
-        {
-            _lastLocation = _lastLocation.Value.WithY(newValue);
-        }
-        else
-        {
-            _lastLocation = new Point(0, newValue);
-        }
+        _lastLocation = _lastLocation?.WithY(newValue) ?? new Point(0, newValue);
     }
 
     private void OnTranslateXChanged(AvaloniaPropertyChangedEventArgs args)
     {
         if (_moving) return;
         var newValue = args.GetNewValue<double>();
-        if (_lastLocation is not null)
-        {
-            _lastLocation = _lastLocation.Value.WithX(newValue);
-        }
-        else
-        {
-            _lastLocation = new Point(newValue, 0);
-        }
+        _lastLocation = _lastLocation?.WithX(newValue) ?? new Point(newValue, 0);
     }
 
     private void OnOverlayerChanged(AvaloniaPropertyChangedEventArgs args)
@@ -181,26 +165,12 @@ public class ImageViewer: TemplatedControl
     {
         var stretch = args.GetNewValue<Stretch>();
         Scale = GetScaleRatio(Width / _image!.Width, Height / _image!.Height, stretch);
-        if(_image is { })
-        {
-            _sourceMinScale = Math.Min(Width * MinScale / _image.Width, Height * MinScale / _image.Height);
-        }
-        else
-        {
-            _sourceMinScale = MinScale;
-        }
+        _sourceMinScale = _image is not null ? Math.Min(Width * MinScale / _image.Width, Height * MinScale / _image.Height) : MinScale;
     }
 
-    private void OnMinScaleChanged(AvaloniaPropertyChangedEventArgs args)
+    private void OnMinScaleChanged(AvaloniaPropertyChangedEventArgs _)
     {
-        if (_image is { })
-        {
-            _sourceMinScale = Math.Min(Width * MinScale / _image.Width, Height * MinScale / _image.Height);
-        }
-        else
-        {
-            _sourceMinScale = MinScale;
-        }
+        _sourceMinScale = _image is not null ? Math.Min(Width * MinScale / _image.Width, Height * MinScale / _image.Height) : MinScale;
 
         if (_sourceMinScale > Scale)
         {
@@ -224,7 +194,7 @@ public class ImageViewer: TemplatedControl
     {
         base.OnApplyTemplate(e);
         _image = e.NameScope.Get<Image>(PART_Image);
-        _layer = e.NameScope.Get<VisualLayerManager>(PART_Layer);
+        e.NameScope.Get<VisualLayerManager>(PART_Layer);
         if (Overlayer is { } c)
         {
             AdornerLayer.SetAdorner(this, c);
@@ -271,7 +241,7 @@ public class ImageViewer: TemplatedControl
     protected override void OnPointerMoved(PointerEventArgs e)
     {
         base.OnPointerMoved(e);
-        if (e.Pointer.Captured == this && _lastClickPoint != null)
+        if (Equals(e.Pointer.Captured, this) && _lastClickPoint != null)
         {
             PseudoClasses.Set(PC_Moving, true);
             Point p = e.GetPosition(this);
diff --git a/src/Ursa/Controls/KeyGestureInput.cs b/src/Ursa/Controls/KeyGestureInput.cs
index 042075b..35eadf3 100644
--- a/src/Ursa/Controls/KeyGestureInput.cs
+++ b/src/Ursa/Controls/KeyGestureInput.cs
@@ -1,6 +1,5 @@
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Controls.Converters;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
diff --git a/src/Ursa/Controls/MessageBox/MessageBoxControl.cs b/src/Ursa/Controls/MessageBox/MessageBoxControl.cs
index 7c1bdbf..fe47e53 100644
--- a/src/Ursa/Controls/MessageBox/MessageBoxControl.cs
+++ b/src/Ursa/Controls/MessageBox/MessageBoxControl.cs
@@ -2,12 +2,8 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
-using Avalonia.Input;
 using Avalonia.Interactivity;
-using Avalonia.Media;
-using Avalonia.Styling;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
 
 namespace Ursa.Controls;
 
@@ -41,7 +37,7 @@ public class MessageBoxControl: DialogControlBase
     }
 
     public static readonly StyledProperty<MessageBoxButton> ButtonsProperty = AvaloniaProperty.Register<MessageBoxControl, MessageBoxButton>(
-        nameof(Buttons), MessageBoxButton.OK);
+        nameof(Buttons));
 
     public MessageBoxButton Buttons
     {
@@ -60,7 +56,7 @@ public class MessageBoxControl: DialogControlBase
     
     static MessageBoxControl()
     {
-        ButtonsProperty.Changed.AddClassHandler<MessageBoxControl>((o, e) => { o.SetButtonVisibility(); });
+        ButtonsProperty.Changed.AddClassHandler<MessageBoxControl>((o, _) => { o.SetButtonVisibility(); });
     }
     
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
@@ -75,7 +71,7 @@ public class MessageBoxControl: DialogControlBase
         SetButtonVisibility();
     }
 
-    private void DefaultButtonsClose(object sender, RoutedEventArgs e)
+    private void DefaultButtonsClose(object? sender, RoutedEventArgs e)
     {
         if (sender is Button button)
         {
diff --git a/src/Ursa/Controls/MessageBox/MessageBoxWindow.cs b/src/Ursa/Controls/MessageBox/MessageBoxWindow.cs
index f270916..ca850c2 100644
--- a/src/Ursa/Controls/MessageBox/MessageBoxWindow.cs
+++ b/src/Ursa/Controls/MessageBox/MessageBoxWindow.cs
@@ -4,9 +4,7 @@ using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
-using Avalonia.Platform;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
 
 namespace Ursa.Controls;
 
@@ -15,7 +13,7 @@ namespace Ursa.Controls;
 [TemplatePart(PART_OKButton, typeof(Button))]
 [TemplatePart(PART_CancelButton, typeof(Button))]
 [TemplatePart(PART_YesButton, typeof(Button))]
-public class MessageBoxWindow : Window
+public class MessageBoxWindow(MessageBoxButton buttons) : Window
 {
     public const string PART_CloseButton = "PART_CloseButton";
     public const string PART_YesButton = "PART_YesButton";
@@ -23,8 +21,6 @@ public class MessageBoxWindow : Window
     public const string PART_OKButton = "PART_OKButton";
     public const string PART_CancelButton = "PART_CancelButton";
 
-    private MessageBoxButton _buttonConfigs;
-
     private Button? _closeButton;
     private Button? _yesButton;
     private Button? _noButton;
@@ -43,14 +39,8 @@ public class MessageBoxWindow : Window
         set => SetValue(MessageIconProperty, value);
     }
 
-    public MessageBoxWindow()
+    public MessageBoxWindow() : this(MessageBoxButton.OK)
     {
-        _buttonConfigs = MessageBoxButton.OK;
-    }
-
-    public MessageBoxWindow(MessageBoxButton buttons)
-    {
-        _buttonConfigs = buttons;
     }
 
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
@@ -70,7 +60,7 @@ public class MessageBoxWindow : Window
 
     private void SetButtonVisibility()
     {
-        switch (_buttonConfigs)
+        switch (buttons)
         {
             case MessageBoxButton.OK:
                 Button.IsVisibleProperty.SetValue(true, _okButton);
@@ -91,9 +81,9 @@ public class MessageBoxWindow : Window
         }
     }
 
-    private void OnCloseButtonClick(object sender, RoutedEventArgs e)
+    private void OnCloseButtonClick(object? sender, RoutedEventArgs e)
     {
-        if (_buttonConfigs == MessageBoxButton.OK)
+        if (buttons == MessageBoxButton.OK)
         {
             Close(MessageBoxResult.OK);
         }
@@ -101,21 +91,21 @@ public class MessageBoxWindow : Window
         Close(MessageBoxResult.Cancel);
     }
 
-    private void OnDefaultButtonClick(object sender, RoutedEventArgs e)
+    private void OnDefaultButtonClick(object? sender, RoutedEventArgs e)
     {
-        if (sender == _okButton)
+        if (Equals(sender, _okButton))
         {
             Close(MessageBoxResult.OK);
         }
-        else if (sender == _cancelButton)
+        else if (Equals(sender, _cancelButton))
         {
             Close(MessageBoxResult.Cancel);
         }
-        else if (sender == _yesButton)
+        else if (Equals(sender, _yesButton))
         {
             Close(MessageBoxResult.Yes);
         }
-        else if (sender == _noButton)
+        else if (Equals(sender, _noButton))
         {
             Close(MessageBoxResult.No);
         }
@@ -124,7 +114,7 @@ public class MessageBoxWindow : Window
     protected override void OnKeyUp(KeyEventArgs e)
     {
         base.OnKeyUp(e);
-        if (e.Key == Key.Escape && _buttonConfigs == MessageBoxButton.OK)
+        if (e.Key == Key.Escape && buttons == MessageBoxButton.OK)
         {
             Close(MessageBoxResult.OK);
         }
diff --git a/src/Ursa/Controls/NavMenu/NavMenu.cs b/src/Ursa/Controls/NavMenu/NavMenu.cs
index ab165e8..7c1e866 100644
--- a/src/Ursa/Controls/NavMenu/NavMenu.cs
+++ b/src/Ursa/Controls/NavMenu/NavMenu.cs
@@ -1,6 +1,4 @@
-using System.Diagnostics;
-using System.Reflection;
-using Avalonia;
+using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
@@ -245,7 +243,7 @@ public class NavMenu: ItemsControl
         _updateFromUI = true;
         foreach (var child in LogicalChildren)
         {
-            if (child == parent)
+            if (Equals(child, parent))
             {
                 continue;
             }
diff --git a/src/Ursa/Controls/NavMenu/NavMenuItem.cs b/src/Ursa/Controls/NavMenu/NavMenuItem.cs
index fc39aa7..e90e1cd 100644
--- a/src/Ursa/Controls/NavMenu/NavMenuItem.cs
+++ b/src/Ursa/Controls/NavMenu/NavMenuItem.cs
@@ -28,12 +28,11 @@ public class NavMenuItem: HeaderedItemsControl
     public const string PC_Selector = ":selector";
     
     private NavMenu? _rootMenu;
-    private Panel? _popupPanel;
     private Popup? _popup;
     private Panel? _overflowPanel;
     
-    private static readonly Point s_invalidPoint = new (double.NaN, double.NaN);
-    private Point _pointerDownPoint = s_invalidPoint;
+    private static readonly Point InvalidPoint = new (double.NaN, double.NaN);
+    private Point _pointerDownPoint = InvalidPoint;
     
     public static readonly StyledProperty<object?> IconProperty = AvaloniaProperty.Register<NavMenuItem, object?>(
         nameof(Icon));
diff --git a/src/Ursa/Controls/NumPad/NumPad.cs b/src/Ursa/Controls/NumPad/NumPad.cs
index 0b0ffc3..3777dab 100644
--- a/src/Ursa/Controls/NumPad/NumPad.cs
+++ b/src/Ursa/Controls/NumPad/NumPad.cs
@@ -1,9 +1,6 @@
 using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
-using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
@@ -51,7 +48,7 @@ public class NumPad: TemplatedControl
         }
     }
     
-    private static void OnTargetGotFocus(object sender, GotFocusEventArgs e)
+    private static void OnTargetGotFocus(object? sender, GotFocusEventArgs e)
     {
         if (sender is not InputElement) return;
         var existing = OverlayDialog.Recall<NumPad>(null);
@@ -87,7 +84,7 @@ public class NumPad: TemplatedControl
     {
         if (Target is null || o is not NumPadButton b) return;
         var key = (b.NumMode ? b.NumKey : b.FunctionKey)?? Key.None;
-        if (KeyInputMapping.TryGetValue(key, out string s))
+        if (KeyInputMapping.TryGetValue(key, out var s))
         {
             Target.RaiseEvent(new TextInputEventArgs()
             {
diff --git a/src/Ursa/Controls/NumberDisplayer/NumberDisplayerBase.cs b/src/Ursa/Controls/NumberDisplayer/NumberDisplayerBase.cs
index b8b174b..2a7e808 100644
--- a/src/Ursa/Controls/NumberDisplayer/NumberDisplayerBase.cs
+++ b/src/Ursa/Controls/NumberDisplayer/NumberDisplayerBase.cs
@@ -8,11 +8,11 @@ namespace Ursa.Controls;
 
 public abstract class NumberDisplayerBase : TemplatedControl
 {
-    public static readonly DirectProperty<NumberDisplayerBase, string> InternalTextProperty = AvaloniaProperty.RegisterDirect<NumberDisplayerBase, string>(
+    public static readonly DirectProperty<NumberDisplayerBase, string?> InternalTextProperty = AvaloniaProperty.RegisterDirect<NumberDisplayerBase, string?>(
         nameof(InternalText), o => o.InternalText, (o, v) => o.InternalText = v);
-    private string _internalText;
+    private string? _internalText;
     
-    public string InternalText
+    public string? InternalText
     {
         get => _internalText;
         set => SetAndRaise(InternalTextProperty, ref _internalText, value);
@@ -51,7 +51,9 @@ public abstract class NumberDisplayer<T>: NumberDisplayerBase
     private Animation? _animation;
     private CancellationTokenSource _cts = new ();
     
+#pragma warning disable AVP1002
     public static readonly StyledProperty<T?> ValueProperty = AvaloniaProperty.Register<NumberDisplayer<T>, T?>(
+#pragma warning restore AVP1002
         nameof(Value), defaultBindingMode:BindingMode.TwoWay);
 
     public T? Value
@@ -60,7 +62,9 @@ public abstract class NumberDisplayer<T>: NumberDisplayerBase
         set => SetValue(ValueProperty, value);
     }
 
+#pragma warning disable AVP1002
     private static readonly StyledProperty<T?> InternalValueProperty = AvaloniaProperty.Register<NumberDisplayer<T>, T?>(
+#pragma warning restore AVP1002
         nameof(InternalValue), defaultBindingMode:BindingMode.TwoWay);
 
     private T? InternalValue
diff --git a/src/Ursa/Controls/NumericUpDown/IntUpDown.cs b/src/Ursa/Controls/NumericUpDown/IntUpDown.cs
index 655a7b1..de1ac48 100644
--- a/src/Ursa/Controls/NumericUpDown/IntUpDown.cs
+++ b/src/Ursa/Controls/NumericUpDown/IntUpDown.cs
@@ -1,8 +1,4 @@
-using System.Globalization;
-using Avalonia.Controls;
-using Avalonia.Utilities;
-
-namespace Ursa.Controls;
+namespace Ursa.Controls;
 
 public class NumericIntUpDown : NumericUpDownBase<int>
 {
diff --git a/src/Ursa/Controls/NumericUpDown/NumericUpDownBase.cs b/src/Ursa/Controls/NumericUpDown/NumericUpDownBase.cs
index fe07226..ed0a380 100644
--- a/src/Ursa/Controls/NumericUpDown/NumericUpDownBase.cs
+++ b/src/Ursa/Controls/NumericUpDown/NumericUpDownBase.cs
@@ -1,6 +1,4 @@
-using System.Diagnostics;
-using System.Globalization;
-using System.Net.Mime;
+using System.Globalization;
 using System.Windows.Input;
 using Avalonia;
 using Avalonia.Controls;
@@ -25,8 +23,8 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl
     public const string PART_TextBox = "PART_TextBox";
     public const string PART_DragPanel = "PART_DragPanel";
 
-    protected internal ButtonSpinner? _spinner;
-    protected internal TextBox? _textBox;
+    protected ButtonSpinner? _spinner;
+    protected TextBox? _textBox;
     protected internal Panel? _dragPanel;
 
     private Point? _point;
@@ -154,7 +152,7 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl
 
     private void OnIsReadOnlyChanged(AvaloniaPropertyChangedEventArgs<bool> args)
     {
-        ChangeToSetSpinDirection(args, false);
+        ChangeToSetSpinDirection(args);
         TextBox.IsReadOnlyProperty.SetValue(args.NewValue.Value, _textBox);
     }
 
@@ -229,7 +227,7 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl
         }
     }
 
-    private void OnDragPanelPointerPressed(object sender, PointerPressedEventArgs e)
+    private void OnDragPanelPointerPressed(object? sender, PointerPressedEventArgs e)
     {
         _point = e.GetPosition(this);
         if (e.ClickCount == 2 && _dragPanel is not null && AllowDrag)
@@ -251,12 +249,12 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl
         _textBox?.RaiseEvent(e);
     }
 
-    private void OnDragPanelPointerReleased(object sender, PointerReleasedEventArgs e)
+    private void OnDragPanelPointerReleased(object? sender, PointerReleasedEventArgs e)
     {
         _point = null;
     }
 
-    private void OnDragPanelPointerMoved(object sender, PointerEventArgs e)
+    private void OnDragPanelPointerMoved(object? sender, PointerEventArgs e)
     {
         if (!AllowDrag || IsReadOnly) return;
         if (!e.GetCurrentPoint(this).Properties.IsLeftButtonPressed) return;
@@ -292,7 +290,7 @@ public abstract class NumericUpDown : TemplatedControl, IClearControl
         };
     }
 
-    private void OnSpin(object sender, SpinEventArgs e)
+    private void OnSpin(object? sender, SpinEventArgs e)
     {
         if (AllowSpin && !IsReadOnly)
         {
@@ -379,7 +377,9 @@ public abstract class NumericUpDownBase<T> : NumericUpDown where T : struct, ICo
         return text;
     }
 
+#pragma warning disable AVP1002
     public static readonly StyledProperty<T?> ValueProperty = AvaloniaProperty.Register<NumericUpDownBase<T>, T?>(
+
         nameof(Value), defaultBindingMode: BindingMode.TwoWay, enableDataValidation: true);
 
     public T? Value
@@ -484,7 +484,7 @@ public abstract class NumericUpDownBase<T> : NumericUpDown where T : struct, ICo
         get => this.GetValue(CommandParameterProperty);
         set => this.SetValue(CommandParameterProperty, value);
     }
-
+#pragma warning restore AVP1002
     protected override void UpdateDataValidation(AvaloniaProperty property, BindingValueType state, Exception? error)
     {
         if (property == ValueProperty)
@@ -525,7 +525,7 @@ public abstract class NumericUpDownBase<T> : NumericUpDown where T : struct, ICo
         ValueProperty.Changed.AddClassHandler<NumericUpDownBase<T>>((o, e) => o.OnValueChanged(e));
     }
 
-    private void OnConstraintChanged(AvaloniaPropertyChangedEventArgs avaloniaPropertyChangedEventArgs)
+    private void OnConstraintChanged(AvaloniaPropertyChangedEventArgs _)
     {
         if (IsInitialized)
         {
@@ -755,6 +755,6 @@ public abstract class NumericUpDownBase<T> : NumericUpDown where T : struct, ICo
     public override void Clear()
     {
         SetCurrentValue(ValueProperty, EmptyInputValue);
-        SyncTextAndValue(false, forceTextUpdate: true);
+        SyncTextAndValue(forceTextUpdate: true);
     }
 }
\ No newline at end of file
diff --git a/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Dialog.cs b/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Dialog.cs
index f41b26c..ed38489 100644
--- a/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Dialog.cs
+++ b/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Dialog.cs
@@ -1,6 +1,6 @@
 using Avalonia;
 using Avalonia.Input;
-using Avalonia.Utilities;
+using Irihi.Avalonia.Shared.Helpers;
 using Irihi.Avalonia.Shared.Shapes;
 using Ursa.Controls.OverlayShared;
 
@@ -57,8 +57,8 @@ public partial class OverlayDialogHost
                 var p = e.GetPosition(this);
                 var left = p.X - _lastPoint.X;
                 var top = p.Y - _lastPoint.Y;
-                left = MathUtilities.Clamp(left, 0, Bounds.Width - item.Bounds.Width);
-                top = MathUtilities.Clamp(top, 0, Bounds.Height - item.Bounds.Height);
+                left = MathHelpers.SafeClamp(left, 0, Bounds.Width - item.Bounds.Width);
+                top = MathHelpers.SafeClamp(top, 0, Bounds.Height - item.Bounds.Height);
                 SetLeft(item, left);
                 SetTop(item, top);
             }
@@ -109,7 +109,7 @@ public partial class OverlayDialogHost
         ResetZIndices();
     }
     
-    private async void OnDialogControlClosing(object sender, object? e)
+    private async void OnDialogControlClosing(object? sender, object? e)
     {
         if (sender is DialogControlBase control)
         {
@@ -175,7 +175,7 @@ public partial class OverlayDialogHost
     }
 
     // Handle dialog layer change event
-    private void OnDialogLayerChanged(object sender, DialogLayerChangeEventArgs e)
+    private void OnDialogLayerChanged(object? sender, DialogLayerChangeEventArgs e)
     {
         if (sender is not DialogControlBase control)
             return;
@@ -187,10 +187,10 @@ public partial class OverlayDialogHost
         switch (e.ChangeType)
         {
             case DialogLayerChangeType.BringForward:
-                newIndex = MathUtilities.Clamp(index + 1, 0, _layers.Count);
+                newIndex = MathHelpers.SafeClamp(index + 1, 0, _layers.Count);
                 break;
             case DialogLayerChangeType.SendBackward:
-                newIndex = MathUtilities.Clamp(index - 1, 0, _layers.Count);
+                newIndex = MathHelpers.SafeClamp(index - 1, 0, _layers.Count);
                 break;
             case DialogLayerChangeType.BringToFront:
                 newIndex = _layers.Count;
@@ -257,19 +257,17 @@ public partial class OverlayDialogHost
 
     private double GetLeftPosition(DialogControlBase control)
     {
-        double left = 0;
+        double left;
         double offset = Math.Max(0, control.HorizontalOffset ?? 0);
         left = this.Bounds.Width - control.Bounds.Width;
         if (control.HorizontalAnchor == HorizontalPosition.Center)
         {
             left *= 0.5;
-            (double min, double max) = MathUtilities.GetMinMax(0, Bounds.Width * 0.5);
-            left = MathUtilities.Clamp(left, min, max);
+            left = MathHelpers.SafeClamp(left, 0, Bounds.Width * 0.5);
         }
         else if (control.HorizontalAnchor == HorizontalPosition.Left)
         {
-            (double min, double max) = MathUtilities.GetMinMax(0, offset);
-            left = MathUtilities.Clamp(left, min, max);
+            left = MathHelpers.SafeClamp(left, 0, offset);
         }
         else if (control.HorizontalAnchor == HorizontalPosition.Right)
         {
@@ -277,7 +275,7 @@ public partial class OverlayDialogHost
             leftOffset = Math.Max(0, leftOffset);
             if(control.HorizontalOffset.HasValue)
             {
-                left = MathUtilities.Clamp(left, 0, leftOffset);
+                left = MathHelpers.SafeClamp(left, 0, leftOffset);
             }
         }
         return left;
@@ -285,23 +283,21 @@ public partial class OverlayDialogHost
 
     private double GetTopPosition(DialogControlBase control)
     {
-        double top = 0;
         double offset = Math.Max(0, control.VerticalOffset ?? 0);
-        top = this.Bounds.Height - control.Bounds.Height;
+        var top = this.Bounds.Height - control.Bounds.Height;
         if (control.VerticalAnchor == VerticalPosition.Center)
         {
             top *= 0.5;
-            (double min, double max) = MathUtilities.GetMinMax(0, Bounds.Height * 0.5);
-            top = MathUtilities.Clamp(top, min, max);
+            top = MathHelpers.SafeClamp(top, 0, Bounds.Height * 0.5);
         }
         else if (control.VerticalAnchor == VerticalPosition.Top)
         {
-            top = MathUtilities.Clamp(top, 0, offset);
+            top = MathHelpers.SafeClamp(top, 0, offset);
         }
         else if (control.VerticalAnchor == VerticalPosition.Bottom)
         {
             var topOffset = Math.Max(0, Bounds.Height - control.Bounds.Height - offset);
-            top = MathUtilities.Clamp(top, 0, topOffset);
+            top = MathHelpers.SafeClamp(top, 0, topOffset);
         }
         return top;
     }
diff --git a/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Drawer.cs b/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Drawer.cs
index 6a893ba..c8da503 100644
--- a/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Drawer.cs
+++ b/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Drawer.cs
@@ -27,7 +27,7 @@ public partial class OverlayDialogHost
         control.Arrange(new Rect(control.DesiredSize));
         SetDrawerPosition(control);
         control.AddHandler(OverlayFeedbackElement.ClosedEvent, OnDrawerControlClosing);
-        var animation = CreateAnimation(control.Bounds.Size, control.Position, true);
+        var animation = CreateAnimation(control.Bounds.Size, control.Position);
         if (IsAnimationDisabled)
         {
             ResetDrawerPosition(control, this.Bounds.Size);
@@ -47,7 +47,7 @@ public partial class OverlayDialogHost
     
     internal async void AddModalDrawer(DrawerControlBase control)
     {
-        PureRectangle? mask = CreateOverlayMask(true, control.CanLightDismiss);
+        PureRectangle mask = CreateOverlayMask(true, control.CanLightDismiss);
         _layers.Add(new DialogPair(mask, control));
         this.Children.Add(mask);
         this.Children.Add(control);
@@ -135,9 +135,11 @@ public partial class OverlayDialogHost
         }
         
         var targetProperty = position==Position.Left || position==Position.Right ? Canvas.LeftProperty : Canvas.TopProperty;
-        var animation = new Animation();
-        animation.Easing = new CubicEaseOut();
-        animation.FillMode = FillMode.Forward;
+        var animation = new Animation
+        {
+            Easing = new CubicEaseOut(),
+            FillMode = FillMode.Forward
+        };
         var keyFrame1 = new KeyFrame(){ Cue = new Cue(0.0) };
         keyFrame1.Setters.Add(new Setter()
             { Property = targetProperty, Value = source });
@@ -150,7 +152,7 @@ public partial class OverlayDialogHost
         return animation;
     }
     
-    private async void OnDrawerControlClosing(object sender, ResultEventArgs e)
+    private async void OnDrawerControlClosing(object? sender, ResultEventArgs e)
     {
         if (sender is DrawerControlBase control)
         {
diff --git a/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Shared.cs b/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Shared.cs
index 212b806..8b09769 100644
--- a/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Shared.cs
+++ b/src/Ursa/Controls/OverlayShared/OverlayDialogHost.Shared.cs
@@ -19,21 +19,14 @@ public partial class OverlayDialogHost: Canvas
 
     private readonly List<DialogPair> _layers = new List<DialogPair>(10);
     
-    private class DialogPair
+    private class DialogPair(PureRectangle? mask, OverlayFeedbackElement element, bool modal = true)
     {
-        internal PureRectangle? Mask;
-        internal OverlayFeedbackElement Element;
-        internal bool Modal;
-
-        public DialogPair(PureRectangle? mask, OverlayFeedbackElement element, bool modal = true)
-        {
-            Mask = mask;
-            Element = element;
-            Modal = modal;
-        }
+        internal readonly PureRectangle? Mask = mask;
+        internal readonly OverlayFeedbackElement Element = element;
+        internal readonly bool Modal = modal;
     }
 
-    private int _modalCount = 0;
+    private int _modalCount;
 
     public static readonly AttachedProperty<bool> IsModalStatusScopeProperty =
         AvaloniaProperty.RegisterAttached<OverlayDialogHost, Control, bool>("IsModalStatusScope");
@@ -73,8 +66,10 @@ public partial class OverlayDialogHost: Canvas
     
     private static Animation CreateOpacityAnimation(bool appear)
     {
-        var animation = new Animation();
-        animation.FillMode = FillMode.Forward;
+        var animation = new Animation
+        {
+            FillMode = FillMode.Forward
+        };
         var keyFrame1 = new KeyFrame{ Cue = new Cue(0.0) };
         keyFrame1.Setters.Add(new Setter() { Property = OpacityProperty, Value = appear ? 0.0 : 1.0 });
         var keyFrame2 = new KeyFrame{ Cue = new Cue(1.0) };
@@ -122,7 +117,7 @@ public partial class OverlayDialogHost: Canvas
         return rec;
     }
     
-    private void ClickMaskToCloseDialog(object sender, PointerReleasedEventArgs e)
+    private void ClickMaskToCloseDialog(object? sender, PointerReleasedEventArgs e)
     {
         if (sender is PureRectangle border)
         {
@@ -209,9 +204,8 @@ public partial class OverlayDialogHost: Canvas
     internal IDataTemplate? GetDataTemplate(object? o)
     {
         if (o is null) return null;
-        IDataTemplate? result = null;
         var templates = this.DialogDataTemplates;
-        result = templates.FirstOrDefault(a => a.Match(o));
+        var result = templates.FirstOrDefault(a => a.Match(o));
         if (result != null) return result;
         var keys = this.Resources.Keys;
         foreach (var key in keys)
diff --git a/src/Ursa/Controls/OverlayShared/OverlayFeedbackElement.cs b/src/Ursa/Controls/OverlayShared/OverlayFeedbackElement.cs
index 02234bf..3daa31e 100644
--- a/src/Ursa/Controls/OverlayShared/OverlayFeedbackElement.cs
+++ b/src/Ursa/Controls/OverlayShared/OverlayFeedbackElement.cs
@@ -24,7 +24,7 @@ public abstract class OverlayFeedbackElement: ContentControl
         ClosedEvent.AddClassHandler<OverlayFeedbackElement>((o,e)=>o.OnClosed(e));
     }
 
-    private void OnClosed(ResultEventArgs arg2)
+    private void OnClosed(ResultEventArgs _)
     {
         SetCurrentValue(IsClosedProperty,true);
     }
@@ -50,12 +50,12 @@ public abstract class OverlayFeedbackElement: ContentControl
         }
     }
     
-    protected virtual void OnElementClosing(object sender, object? args)
+    protected virtual void OnElementClosing(object? sender, object? args)
     {
         RaiseEvent(new ResultEventArgs(ClosedEvent, args));
     }
     
-    private void OnContextRequestClose(object sender, object? args)
+    private void OnContextRequestClose(object? sender, object? args)
     {
         RaiseEvent(new ResultEventArgs(ClosedEvent, args));
     }
@@ -68,7 +68,7 @@ public abstract class OverlayFeedbackElement: ContentControl
             Dispatcher.UIThread.Invoke(Close);
         });
         
-        void OnCloseHandler(object sender, ResultEventArgs? args)
+        void OnCloseHandler(object? sender, ResultEventArgs? args)
         {
             if (args?.Result is T result)
             {
diff --git a/src/Ursa/Controls/Pagination/Pagination.cs b/src/Ursa/Controls/Pagination/Pagination.cs
index 78b3793..cac9b54 100644
--- a/src/Ursa/Controls/Pagination/Pagination.cs
+++ b/src/Ursa/Controls/Pagination/Pagination.cs
@@ -159,7 +159,7 @@ public class Pagination: TemplatedControl
             pagination.UpdateButtonsByCurrentPage(args.NewValue.Value));
         CurrentPageProperty.Changed.AddClassHandler<Pagination, int?>((pagination, args) =>
             pagination.OnCurrentPageChanged(args));
-        TotalCountProperty.Changed.AddClassHandler<Pagination, int>((pagination, args) =>
+        TotalCountProperty.Changed.AddClassHandler<Pagination, int>((pagination, _) =>
             pagination.UpdateButtonsByCurrentPage(pagination.CurrentPage));
     }
 
@@ -199,7 +199,7 @@ public class Pagination: TemplatedControl
         UpdateButtonsByCurrentPage(0);
     }
 
-    private void OnQuickJumpInputKeyDown(object sender, KeyEventArgs e)
+    private void OnQuickJumpInputKeyDown(object? sender, KeyEventArgs e)
     {
         if (e.Key is Key.Enter or Key.Return)
         {
@@ -207,7 +207,7 @@ public class Pagination: TemplatedControl
         }
     }
 
-    private void OnQuickJumpInputLostFocus(object sender, RoutedEventArgs e)
+    private void OnQuickJumpInputLostFocus(object? sender, RoutedEventArgs e)
     {
         SyncQuickJumperValue();
     }
@@ -238,12 +238,12 @@ public class Pagination: TemplatedControl
         {
             var button = new PaginationButton() { Page = i, IsVisible = true };
             _buttonPanel.Children.Add(button);
-            _buttons![i - 1] = button;
+            _buttons[i - 1] = button;
             Button.ClickEvent.AddHandler(OnPageButtonClick, button);
         }
     }
 
-    private void OnPageButtonClick(object sender, RoutedEventArgs args)
+    private void OnPageButtonClick(object? sender, RoutedEventArgs args)
     {
         if (sender is PaginationButton pageButton)
         {
diff --git a/src/Ursa/Controls/Pagination/PaginationButton.cs b/src/Ursa/Controls/Pagination/PaginationButton.cs
index 9f87f38..b05babc 100644
--- a/src/Ursa/Controls/Pagination/PaginationButton.cs
+++ b/src/Ursa/Controls/Pagination/PaginationButton.cs
@@ -1,8 +1,6 @@
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
-using Avalonia.Controls.Primitives;
-using Avalonia.Styling;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/RangeSlider/RangeSlider.cs b/src/Ursa/Controls/RangeSlider/RangeSlider.cs
index e7351ad..533724a 100644
--- a/src/Ursa/Controls/RangeSlider/RangeSlider.cs
+++ b/src/Ursa/Controls/RangeSlider/RangeSlider.cs
@@ -1,4 +1,3 @@
-using System.Runtime.CompilerServices;
 using Avalonia;
 using Avalonia.Collections;
 using Avalonia.Controls;
@@ -178,7 +177,7 @@ public class RangeSlider: TemplatedControl
 
     private Thumb? _currentThumb;
     
-    private void PointerPress(object sender, PointerPressedEventArgs e)
+    private void PointerPress(object? sender, PointerPressedEventArgs e)
     {
         if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed)
         {
@@ -189,7 +188,7 @@ public class RangeSlider: TemplatedControl
         }
     }
     
-    private void PointerMove(object sender, PointerEventArgs args)
+    private void PointerMove(object? sender, PointerEventArgs args)
     {
         if (!IsEnabled)
         {
@@ -202,7 +201,7 @@ public class RangeSlider: TemplatedControl
         }
     }
     
-    private void PointerRelease(object sender, PointerReleasedEventArgs e)
+    private void PointerRelease(object? sender, PointerReleasedEventArgs e)
     {
         _isDragging = false;
         _currentThumb = null;
diff --git a/src/Ursa/Controls/RangeSlider/RangeTrack.cs b/src/Ursa/Controls/RangeSlider/RangeTrack.cs
index a6995dd..126cb4f 100644
--- a/src/Ursa/Controls/RangeSlider/RangeTrack.cs
+++ b/src/Ursa/Controls/RangeSlider/RangeTrack.cs
@@ -1,13 +1,11 @@
-using System.Diagnostics;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Data;
-using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Layout;
-using Avalonia.Utilities;
+using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
 
@@ -20,8 +18,6 @@ public class RangeTrack: Control
 {
     public const string PC_Horizontal = ":horizontal";
     public const string PC_Vertical = ":vertical";
-    private double _density;
-    private Vector _lastDrag;
 
     private const double Tolerance = 0.0001;
 
@@ -173,7 +169,7 @@ public class RangeTrack: Control
         }
     }
 
-    private void OnMinimumChanged(AvaloniaPropertyChangedEventArgs<double> avaloniaPropertyChangedEventArgs)
+    private void OnMinimumChanged(AvaloniaPropertyChangedEventArgs<double> _)
     {
         if (IsInitialized)
         {
@@ -183,7 +179,7 @@ public class RangeTrack: Control
         }
     }
     
-    private void OnMaximumChanged(AvaloniaPropertyChangedEventArgs<double> avaloniaPropertyChangedEventArgs)
+    private void OnMaximumChanged(AvaloniaPropertyChangedEventArgs<double> _)
     {
         if (IsInitialized)
         {
@@ -247,16 +243,16 @@ public class RangeTrack: Control
     private static double CoerceLowerValue(AvaloniaObject sender, double value)
     {
         if (!ValidateDouble(value)) return sender.GetValue(LowerValueProperty);
-        value = MathUtilities.Clamp(value, sender.GetValue(MinimumProperty), sender.GetValue(MaximumProperty));
-        value = MathUtilities.Clamp(value, sender.GetValue(MinimumProperty), sender.GetValue(UpperValueProperty));
+        value = MathHelpers.SafeClamp(value, sender.GetValue(MinimumProperty), sender.GetValue(MaximumProperty));
+        value = MathHelpers.SafeClamp(value, sender.GetValue(MinimumProperty), sender.GetValue(UpperValueProperty));
         return value;
     }
 
     private static double CoerceUpperValue(AvaloniaObject sender, double value)
     {
         if (!ValidateDouble(value)) return sender.GetValue(UpperValueProperty);
-        value = MathUtilities.Clamp(value, sender.GetValue(MinimumProperty), sender.GetValue(MaximumProperty));
-        value = MathUtilities.Clamp(value, sender.GetValue(LowerValueProperty), sender.GetValue(MaximumProperty));
+        value = MathHelpers.SafeClamp(value, sender.GetValue(MinimumProperty), sender.GetValue(MaximumProperty));
+        value = MathHelpers.SafeClamp(value, sender.GetValue(LowerValueProperty), sender.GetValue(MaximumProperty));
         return value;
     }
 
@@ -292,9 +288,8 @@ public class RangeTrack: Control
     protected override Size ArrangeOverride(Size finalSize)
     {
         var vertical = Orientation == Orientation.Vertical;
-        double lowerButtonLength, innerButtonLength, upperButtonLength, lowerThumbLength, upperThumbLength;
-        ComputeSliderLengths(finalSize, vertical, out lowerButtonLength, out innerButtonLength, out upperButtonLength,
-            out lowerThumbLength, out upperThumbLength);
+        ComputeSliderLengths(finalSize, vertical, out var lowerButtonLength, out var innerButtonLength, out var upperButtonLength,
+            out var lowerThumbLength, out var upperThumbLength);
         var offset = new Point();
         var pieceSize = finalSize;
         if (vertical)
@@ -433,8 +428,6 @@ public class RangeTrack: Control
         lowerButtonLength = remainingLength * lowerOffset / range;
         upperButtonLength = remainingLength * (range-upperOffset) / range;
         innerButtonLength = remainingLength - lowerButtonLength - upperButtonLength;
-
-        _density = range / remainingLength;
     }
 
     private static void CoerceLength(ref double componentLength, double trackLength)
diff --git a/src/Ursa/Controls/ScrollTo/ScrollTo.cs b/src/Ursa/Controls/ScrollTo/ScrollTo.cs
index fc1dcfb..070f981 100644
--- a/src/Ursa/Controls/ScrollTo/ScrollTo.cs
+++ b/src/Ursa/Controls/ScrollTo/ScrollTo.cs
@@ -29,7 +29,6 @@ public class ScrollTo
     private static void OnButtonThemeChanged(Control arg1, AvaloniaPropertyChangedEventArgs<ControlTheme?> arg2)
     {
         var button = EnsureButtonInAdorner(arg1);
-        if (button is null) return;
         button.SetCurrentValue(StyledElement.ThemeProperty, arg2.NewValue.Value);
     }
 
@@ -37,11 +36,10 @@ public class ScrollTo
     {
         if (args.NewValue.Value is null) return;
         var button = EnsureButtonInAdorner(control);
-        if (button is null) return;
         button.SetCurrentValue(ScrollToButton.DirectionProperty, args.NewValue.Value);
     }
 
-    private static ScrollToButton? EnsureButtonInAdorner(Control control)
+    private static ScrollToButton EnsureButtonInAdorner(Control control)
     {
         var adorner = AdornerLayer.GetAdorner(control);
         if (adorner is not ScrollToButton button)
diff --git a/src/Ursa/Controls/ScrollTo/ScrollToButton.cs b/src/Ursa/Controls/ScrollTo/ScrollToButton.cs
index 51a1df3..4b0be69 100644
--- a/src/Ursa/Controls/ScrollTo/ScrollToButton.cs
+++ b/src/Ursa/Controls/ScrollTo/ScrollToButton.cs
@@ -1,12 +1,7 @@
 using Avalonia;
-using Avalonia.Animation;
-using Avalonia.Animation.Easings;
 using Avalonia.Controls;
 using Avalonia.Interactivity;
-using Avalonia.LogicalTree;
-using Avalonia.Styling;
 using Avalonia.VisualTree;
-using Irihi.Avalonia.Shared.Helpers;
 using Ursa.Common;
 
 namespace Ursa.Controls;
@@ -64,7 +59,7 @@ public class ScrollToButton: Button
         }
     }
 
-    protected override async void OnClick()
+    protected override void OnClick()
     {
         if (_scroll is null) return;
         var vector = Direction switch
diff --git a/src/Ursa/Controls/SelectionList/SelectionList.cs b/src/Ursa/Controls/SelectionList/SelectionList.cs
index 916a446..1226032 100644
--- a/src/Ursa/Controls/SelectionList/SelectionList.cs
+++ b/src/Ursa/Controls/SelectionList/SelectionList.cs
@@ -1,4 +1,3 @@
-using System.Runtime.CompilerServices;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
@@ -37,7 +36,7 @@ public class SelectionList: SelectingItemsControl
         SelectionModeProperty.OverrideMetadata<SelectionList>(
             new StyledPropertyMetadata<SelectionMode>(
             defaultValue: SelectionMode.Single, 
-            coerce: (o, mode) => SelectionMode.Single)
+            coerce: (_, _) => SelectionMode.Single)
             );
         SelectedItemProperty.Changed.AddClassHandler<SelectionList, object?>((list, args) =>
             list.OnSelectedItemChanged(args));
diff --git a/src/Ursa/Controls/SelectionList/SelectionListItem.cs b/src/Ursa/Controls/SelectionList/SelectionListItem.cs
index 1e89704..4621176 100644
--- a/src/Ursa/Controls/SelectionList/SelectionListItem.cs
+++ b/src/Ursa/Controls/SelectionList/SelectionListItem.cs
@@ -14,9 +14,6 @@ public class SelectionListItem: ContentControl, ISelectable
         PressedMixin.Attach<SelectionListItem>();
         FocusableProperty.OverrideDefaultValue<SelectionListItem>(true);
     }
-    
-    private static readonly Point s_invalidPoint = new Point(double.NaN, double.NaN);
-    private Point _pointerDownPoint = s_invalidPoint;
 
     public static readonly StyledProperty<bool> IsSelectedProperty = SelectingItemsControl.IsSelectedProperty.AddOwner<ListBoxItem>();
 
@@ -29,7 +26,7 @@ public class SelectionListItem: ContentControl, ISelectable
     protected override void OnPointerPressed(PointerPressedEventArgs e)
     {
         base.OnPointerPressed(e);
-        if (ItemsControl.ItemsControlFromItemContaner(this) is SelectionList list)
+        if (ItemsControl.ItemsControlFromItemContainer(this) is SelectionList list)
         {
             int index = list.IndexFromContainer(this);
             list.SelectByIndex(index);
diff --git a/src/Ursa/Controls/Skeleton.cs b/src/Ursa/Controls/Skeleton.cs
index 78ede92..81e26e3 100644
--- a/src/Ursa/Controls/Skeleton.cs
+++ b/src/Ursa/Controls/Skeleton.cs
@@ -1,8 +1,5 @@
 using Avalonia;
 using Avalonia.Controls;
-using System;
-using System.Collections.Generic;
-using System.Text;
 
 namespace Ursa.Controls
 {
diff --git a/src/Ursa/Controls/TagInput/TagInput.cs b/src/Ursa/Controls/TagInput/TagInput.cs
index 4cdba32..f464641 100644
--- a/src/Ursa/Controls/TagInput/TagInput.cs
+++ b/src/Ursa/Controls/TagInput/TagInput.cs
@@ -91,8 +91,10 @@ public class TagInput : TemplatedControl
 
     public TagInput()
     {
-        _textBox = new TextBox();
-        _textBox[!AcceptsReturnProperty] = this.GetObservable(AcceptsReturnProperty).ToBinding();
+        _textBox = new TextBox
+        {
+            [!AcceptsReturnProperty] = this.GetObservable(AcceptsReturnProperty).ToBinding()
+        };
         _textBox.AddHandler(KeyDownEvent, OnTextBoxKeyDown, RoutingStrategies.Tunnel);
         _textBox.AddHandler(LostFocusEvent, OnTextBox_LostFocus, RoutingStrategies.Bubble);
         Items = new AvaloniaList<object>
@@ -230,18 +232,20 @@ public class TagInput : TemplatedControl
         }
 
         if (newTags != null)
-            for (var i = 0; i < newTags.Count; i++)
-                Items.Insert(Items.Count - 1, newTags[i]);
+            foreach (var newTag in newTags)
+                Items.Insert(Items.Count - 1, newTag);
+
         if (oldTags is INotifyCollectionChanged inccold) inccold.CollectionChanged -= OnCollectionChanged;
 
         if (Tags is INotifyCollectionChanged incc) incc.CollectionChanged += OnCollectionChanged;
     }
 
-    private void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+    private void OnCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
     {
         if (e.Action == NotifyCollectionChangedAction.Add)
         {
             var items = e.NewItems;
+            if (items is null) return;
             var index = e.NewStartingIndex;
             foreach (var item in items)
                 if (item is string s)
@@ -253,6 +257,7 @@ public class TagInput : TemplatedControl
         else if (e.Action == NotifyCollectionChangedAction.Remove)
         {
             var items = e.OldItems;
+            if (items is null) return;
             var index = e.OldStartingIndex;
             foreach (var item in items)
                 if (item is string)
@@ -295,21 +300,21 @@ public class TagInput : TemplatedControl
     {
         if (!(text?.Length > 0)) return;
         if (Tags.Count >= MaxCount) return;
-        string[] values;
+        string[] values = [];
         if (!string.IsNullOrEmpty(Separator))
             values = text.Split(new[] { Separator },
                 StringSplitOptions.RemoveEmptyEntries);
-        else
+        else if(_textBox.Text is not null)
             values = new[] { _textBox.Text };
 
         if (!AllowDuplicates)
             values = values.Distinct().Except(Tags).ToArray();
 
-        for (var i = 0; i < values.Length; i++)
+        foreach (var value in values)
         {
             var index = Items.Count - 1;
             // Items.Insert(index, values[i]);
-            Tags?.Insert(index, values[i]);
+            Tags?.Insert(index, value);
         }
 
         _textBox.Clear();
diff --git a/src/Ursa/Controls/ThemeSelector/ThemeSelectorBase.cs b/src/Ursa/Controls/ThemeSelector/ThemeSelectorBase.cs
index 343b7cc..4ba888a 100644
--- a/src/Ursa/Controls/ThemeSelector/ThemeSelectorBase.cs
+++ b/src/Ursa/Controls/ThemeSelector/ThemeSelectorBase.cs
@@ -3,8 +3,6 @@ using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.LogicalTree;
 using Avalonia.Styling;
-using Ursa.Common;
-using System;
 
 namespace Ursa.Controls;
 
@@ -61,7 +59,7 @@ public abstract class ThemeSelectorBase: TemplatedControl
         }
     }
 
-    private void OnScopeThemeChanged(object sender, System.EventArgs e)
+    private void OnScopeThemeChanged(object? sender, System.EventArgs e)
     {
         _syncFromScope = true;
         if (this.TargetScope is { } target)
@@ -149,7 +147,6 @@ public abstract class ThemeSelectorBase: TemplatedControl
         if (_application is not null)
         {
             _application.RequestedThemeVariant = newTheme;
-            return;
         }
     }
 }
\ No newline at end of file
diff --git a/src/Ursa/Controls/ThemeSelector/ThemeToggleButton.cs b/src/Ursa/Controls/ThemeSelector/ThemeToggleButton.cs
index 037e0d5..fcfd2cc 100644
--- a/src/Ursa/Controls/ThemeSelector/ThemeToggleButton.cs
+++ b/src/Ursa/Controls/ThemeSelector/ThemeToggleButton.cs
@@ -5,7 +5,6 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
 using Avalonia.Styling;
 using Irihi.Avalonia.Shared.Helpers;
-using Ursa.Common;
 
 namespace Ursa.Controls;
 
@@ -40,7 +39,7 @@ public class ThemeToggleButton: ThemeSelectorBase
         // ToggleButton.IsCheckedProperty.SetValue(_currentTheme == ThemeVariant.Light, _button);
     }
 
-    private void OnButtonClicked(object sender, RoutedEventArgs e)
+    private void OnButtonClicked(object? sender, RoutedEventArgs e)
     {
         bool? currentState = _state;
         if (IsThreeState)
diff --git a/src/Ursa/Controls/TimeBox.cs b/src/Ursa/Controls/TimeBox.cs
index 88b482b..53831db 100644
--- a/src/Ursa/Controls/TimeBox.cs
+++ b/src/Ursa/Controls/TimeBox.cs
@@ -272,7 +272,7 @@ public class TimeBox : TemplatedControl
         if (e.Handled) return;
         string? s = e.Text;
         if (string.IsNullOrEmpty(s)) return;
-        if (!char.IsNumber(s![0])) return;
+        if (!char.IsNumber(s[0])) return;
         if (_currentActiveSectionIndex is null) return;
 
         int caretIndex = Math.Min(_presenters[_currentActiveSectionIndex.Value].CaretIndex
@@ -332,7 +332,11 @@ public class TimeBox : TemplatedControl
                 MoveCaret(_currentActiveSectionIndex.Value);
             }
         }
-        e.Pointer.Capture(_presenters[_currentActiveSectionIndex.Value]);
+
+        if (_currentActiveSectionIndex is not null)
+        {
+            e.Pointer.Capture(_presenters[_currentActiveSectionIndex.Value]);
+        }
         e.Handled = true;
     }
 
@@ -427,7 +431,7 @@ public class TimeBox : TemplatedControl
         _milliSecondText?.SetValue(TextPresenter.TextProperty, _values[3].ToString(millisecondformat));
     }
 
-    private void OnDragPanelPointerMoved(object sender, PointerEventArgs e)
+    private void OnDragPanelPointerMoved(object? sender, PointerEventArgs e)
     {
         if (!AllowDrag) return;
         if (!e.GetCurrentPoint(this).Properties.IsLeftButtonPressed) return;
@@ -595,7 +599,7 @@ public class TimeBox : TemplatedControl
     private void DeleteImplementation(int index)
     {
         if (index < 0 || index > 3) return;
-        var oldText = _presenters[index].Text;
+        var oldText = _presenters[index].Text??string.Empty;
         if (_presenters[index].SelectionStart != _presenters[index].SelectionEnd)
         {
             _presenters[index].DeleteSelection();
@@ -608,8 +612,8 @@ public class TimeBox : TemplatedControl
         else
         {
             int caretIndex = _presenters[index].CaretIndex;
-            string newText = oldText?.Substring(0, caretIndex - 1) +
-                             oldText?.Substring(Math.Min(caretIndex, oldText.Length));
+            string newText = oldText.Substring(0, caretIndex - 1) +
+                             oldText.Substring(Math.Min(caretIndex, oldText.Length));
             _presenters[index].MoveCaretHorizontal(LogicalDirection.Backward);
             _presenters[index].Text = newText;
         }
@@ -622,7 +626,7 @@ public class TimeBox : TemplatedControl
         _values[index] += lowerCarry;
         int carry = _values[index] >= 0 ? _values[index] / _limits[index] : -1 + (_values[index] / _limits[index]);
         if (carry == 0) return true;
-        bool success = false;
+        bool success;
         if (carry > 0)
         {
             success = HandlingCarry(index - 1, carry);
diff --git a/src/Ursa/Controls/Timeline/Timeline.cs b/src/Ursa/Controls/Timeline/Timeline.cs
index a318a58..1d22895 100644
--- a/src/Ursa/Controls/Timeline/Timeline.cs
+++ b/src/Ursa/Controls/Timeline/Timeline.cs
@@ -1,12 +1,8 @@
-using System.Collections.Specialized;
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Controls.Generators;
-using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.Data;
-using Avalonia.Layout;
 using Avalonia.Metadata;
 
 namespace Ursa.Controls;
@@ -162,7 +158,10 @@ public class Timeline: ItemsControl
     protected override Size ArrangeOverride(Size finalSize)
     {
         var panel = this.ItemsPanelRoot as TimelinePanel;
-        panel.Mode = this.Mode;
+        if (panel is not null)
+        {
+            panel.Mode = this.Mode;
+        }
         SetItemMode();
         return base.ArrangeOverride(finalSize);
     }
@@ -195,17 +194,11 @@ public class Timeline: ItemsControl
             }
             else if (Mode == TimelineDisplayMode.Alternate)
             {
-                bool left = false;
+                var left = false;
                 foreach (var item in items)
                 {
-                    if (left)
-                    {
-                        SetIfUnset(item, TimelineItem.PositionProperty, TimelineItemPosition.Left);
-                    }
-                    else
-                    {
-                        SetIfUnset(item, TimelineItem.PositionProperty, TimelineItemPosition.Right);
-                    }
+                    SetIfUnset(item, TimelineItem.PositionProperty,
+                        left ? TimelineItemPosition.Left : TimelineItemPosition.Right);
                     left = !left;
                 }
             }
diff --git a/src/Ursa/Controls/Timeline/TimelineFormatConverter.cs b/src/Ursa/Controls/Timeline/TimelineFormatConverter.cs
index 48cdc8f..ec22441 100644
--- a/src/Ursa/Controls/Timeline/TimelineFormatConverter.cs
+++ b/src/Ursa/Controls/Timeline/TimelineFormatConverter.cs
@@ -6,7 +6,7 @@ namespace Ursa.Controls;
 
 public class TimelineFormatConverter: IMultiValueConverter
 {
-    public object? Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
     {
         if (values.Count> 1 && values[0] is DateTime date && values[1] is string s)
         {
diff --git a/src/Ursa/Controls/Timeline/TimelineItem.cs b/src/Ursa/Controls/Timeline/TimelineItem.cs
index 9eecece..1239450 100644
--- a/src/Ursa/Controls/Timeline/TimelineItem.cs
+++ b/src/Ursa/Controls/Timeline/TimelineItem.cs
@@ -4,8 +4,6 @@ using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
-using Avalonia.Data;
-using Avalonia.Media;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/Timeline/TimelinePanel.cs b/src/Ursa/Controls/Timeline/TimelinePanel.cs
index e496558..2bc0a97 100644
--- a/src/Ursa/Controls/Timeline/TimelinePanel.cs
+++ b/src/Ursa/Controls/Timeline/TimelinePanel.cs
@@ -1,6 +1,5 @@
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Layout;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/TitleBar/CaptionButtons.cs b/src/Ursa/Controls/TitleBar/CaptionButtons.cs
index 3fd913c..4356fa9 100644
--- a/src/Ursa/Controls/TitleBar/CaptionButtons.cs
+++ b/src/Ursa/Controls/TitleBar/CaptionButtons.cs
@@ -3,7 +3,6 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Irihi.Avalonia.Shared.Helpers;
-using Irihi.Avalonia.Shared.Reactive;
 
 namespace Ursa.Controls;
 
@@ -36,10 +35,10 @@ public class CaptionButtons: Avalonia.Controls.Chrome.CaptionButtons
         _restoreButton = e.NameScope.Get<Button>(PART_RestoreButton);
         _minimizeButton = e.NameScope.Get<Button>(PART_MinimizeButton);
         _fullScreenButton = e.NameScope.Get<Button>(PART_FullScreenButton);
-        Button.ClickEvent.AddHandler((o, args) => OnClose(), _closeButton);
-        Button.ClickEvent.AddHandler((o, args) => OnRestore(), _restoreButton);
-        Button.ClickEvent.AddHandler((o, args) => OnMinimize(), _minimizeButton);
-        Button.ClickEvent.AddHandler((o, args) => OnToggleFullScreen(), _fullScreenButton);
+        Button.ClickEvent.AddHandler((_, _) => OnClose(), _closeButton);
+        Button.ClickEvent.AddHandler((_, _) => OnRestore(), _restoreButton);
+        Button.ClickEvent.AddHandler((_, _) => OnMinimize(), _minimizeButton);
+        Button.ClickEvent.AddHandler((_, _) => OnToggleFullScreen(), _fullScreenButton);
 
         Window.WindowStateProperty.Changed.AddClassHandler<Window, WindowState>(WindowStateChanged);
         if (this.HostWindow is not null && !HostWindow.CanResize)
@@ -75,7 +74,7 @@ public class CaptionButtons: Avalonia.Controls.Chrome.CaptionButtons
     public override void Attach(Window hostWindow)
     {
         base.Attach(hostWindow);
-        _visibilityDisposable = HostWindow?.GetObservable(Window.WindowStateProperty).Subscribe((a) =>
+        _visibilityDisposable = HostWindow?.GetObservable(Window.WindowStateProperty).Subscribe((_) =>
         {
             UpdateVisibility();
         });
diff --git a/src/Ursa/Controls/TitleBar/TitleBar.cs b/src/Ursa/Controls/TitleBar/TitleBar.cs
index 36dcaea..d06e921 100644
--- a/src/Ursa/Controls/TitleBar/TitleBar.cs
+++ b/src/Ursa/Controls/TitleBar/TitleBar.cs
@@ -1,9 +1,7 @@
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
-using Avalonia.Platform;
 using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
@@ -47,7 +45,7 @@ public class TitleBar: ContentControl
         // this.UpdateSize(visualRoot);
     }
 
-    private void OnPointerPressed(object sender, PointerPressedEventArgs e)
+    private void OnPointerPressed(object? sender, PointerPressedEventArgs e)
     {
         if(_visualRoot is not null
             && _visualRoot.WindowState == WindowState.FullScreen)
@@ -63,7 +61,7 @@ public class TitleBar: ContentControl
         }
     }
 
-    private void OnDoubleTapped(object sender, TappedEventArgs e)
+    private void OnDoubleTapped(object? sender, TappedEventArgs e)
     {
         if (_visualRoot is not null)
         {
diff --git a/src/Ursa/Controls/ToolBar/ToolBar.cs b/src/Ursa/Controls/ToolBar/ToolBar.cs
index 5259247..691272d 100644
--- a/src/Ursa/Controls/ToolBar/ToolBar.cs
+++ b/src/Ursa/Controls/ToolBar/ToolBar.cs
@@ -5,8 +5,6 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.Layout;
-using Avalonia.Markup.Xaml.Templates;
-using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/ToolBar/ToolBarSeparator.cs b/src/Ursa/Controls/ToolBar/ToolBarSeparator.cs
index 24a9648..212d60b 100644
--- a/src/Ursa/Controls/ToolBar/ToolBarSeparator.cs
+++ b/src/Ursa/Controls/ToolBar/ToolBarSeparator.cs
@@ -4,7 +4,6 @@ using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Layout;
 using Avalonia.LogicalTree;
-using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/VerificationCode/VerificationCode.cs b/src/Ursa/Controls/VerificationCode/VerificationCode.cs
index 3fcfa46..8563bf6 100644
--- a/src/Ursa/Controls/VerificationCode/VerificationCode.cs
+++ b/src/Ursa/Controls/VerificationCode/VerificationCode.cs
@@ -1,14 +1,10 @@
 using System.Windows.Input;
 using Avalonia;
-using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
-using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
-using Avalonia.LogicalTree;
-using Avalonia.Utilities;
 using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
@@ -18,7 +14,7 @@ public class VerificationCode: TemplatedControl
 {
     public const string PART_ItemsControl = "PART_ItemsControl";
     private ItemsControl? _itemsControl;
-    private int _currentIndex = 0;
+    private int _currentIndex;
     
     public static readonly StyledProperty<ICommand?> CompleteCommandProperty = AvaloniaProperty.Register<VerificationCode, ICommand?>(
         nameof(CompleteCommand));
@@ -105,9 +101,9 @@ public class VerificationCode: TemplatedControl
         PointerPressedEvent.AddHandler(OnControlPressed, RoutingStrategies.Tunnel, false, this);
     }
 
-    private void OnControlPressed(object sender, PointerPressedEventArgs e)
+    private void OnControlPressed(object? sender, PointerPressedEventArgs e)
     {
-        if (e.Source is Control t)
+        if (e.Source is Control)
         {
             /*
             var item = t.FindLogicalAncestorOfType<VerificationCodeItem>();
@@ -117,7 +113,7 @@ public class VerificationCode: TemplatedControl
                 _currentIndex = _itemsControl?.IndexFromContainer(item) ?? 0;
             }
             */
-            _currentIndex = MathUtilities.Clamp(_currentIndex, 0, Count - 1);
+            _currentIndex = MathHelpers.SafeClamp(_currentIndex, 0, Count - 1);
             _itemsControl?.ContainerFromIndex(_currentIndex)?.Focus();
         }
         e.Handled = true;
@@ -162,7 +158,7 @@ public class VerificationCode: TemplatedControl
         base.OnKeyDown(e);
         if (e.Key == Key.Back && _currentIndex >= 0)
         {
-            _currentIndex = MathUtilities.Clamp(_currentIndex, 0, Count - 1);
+            _currentIndex = MathHelpers.SafeClamp(_currentIndex, 0, Count - 1);
             var presenter = _itemsControl?.ContainerFromIndex(_currentIndex) as VerificationCodeItem;
             if (presenter is null) return;
             Digits[_currentIndex] = string.Empty;
diff --git a/src/Ursa/Controls/VerificationCode/VerificationCodeCollection.cs b/src/Ursa/Controls/VerificationCode/VerificationCodeCollection.cs
index e403c87..0bf0dd5 100644
--- a/src/Ursa/Controls/VerificationCode/VerificationCodeCollection.cs
+++ b/src/Ursa/Controls/VerificationCode/VerificationCodeCollection.cs
@@ -1,9 +1,5 @@
-using Avalonia;
-using Avalonia.Controls;
-using Avalonia.Controls.Presenters;
-using Avalonia.Data;
+using Avalonia.Controls;
 using Avalonia.Input;
-using Avalonia.Media;
 
 namespace Ursa.Controls;
 
diff --git a/src/Ursa/Controls/VerificationCode/VerificationCodeCompleteEventArgs.cs b/src/Ursa/Controls/VerificationCode/VerificationCodeCompleteEventArgs.cs
index e1422cf..7fc285e 100644
--- a/src/Ursa/Controls/VerificationCode/VerificationCodeCompleteEventArgs.cs
+++ b/src/Ursa/Controls/VerificationCode/VerificationCodeCompleteEventArgs.cs
@@ -1,4 +1,3 @@
-using Avalonia.Collections;
 using Avalonia.Interactivity;
 
 namespace Ursa.Controls;
diff --git a/src/Ursa/Converters/CornerRadiusConverter.cs b/src/Ursa/Converters/CornerRadiusConverter.cs
index a5e041a..759a1c7 100644
--- a/src/Ursa/Converters/CornerRadiusConverter.cs
+++ b/src/Ursa/Converters/CornerRadiusConverter.cs
@@ -17,7 +17,7 @@ public enum CornerRadiusPosition
     Bottom = 12,
 }
 
-public class CornerRadiusIncludeConverter: IValueConverter
+public class CornerRadiusIncludeConverter(CornerRadiusPosition position) : IValueConverter
 {
     public static CornerRadiusIncludeConverter TopLeft { get; } = new( CornerRadiusPosition.TopLeft );
     public static CornerRadiusIncludeConverter TopRight { get; } = new( CornerRadiusPosition.TopRight );
@@ -27,27 +27,21 @@ public class CornerRadiusIncludeConverter: IValueConverter
     public static CornerRadiusIncludeConverter Left { get; } = new( CornerRadiusPosition.Left );
     public static CornerRadiusIncludeConverter Right { get; } = new( CornerRadiusPosition.Right );
     public static CornerRadiusIncludeConverter Bottom { get; } = new( CornerRadiusPosition.Bottom );
-    
-    private readonly CornerRadiusPosition _position;
-    
-    public CornerRadiusIncludeConverter(CornerRadiusPosition position)
-    {
-        _position = position;
-    }
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is CornerRadius r)
         {
-            double topLeft = _position.HasFlag(CornerRadiusPosition.TopLeft) ? r.TopLeft : 0;
-            double topRight = _position.HasFlag(CornerRadiusPosition.TopRight) ? r.TopRight : 0;
-            double bottomLeft = _position.HasFlag(CornerRadiusPosition.BottomLeft) ? r.BottomLeft : 0;
-            double bottomRight = _position.HasFlag(CornerRadiusPosition.BottomRight) ? r.BottomRight : 0;
+            double topLeft = position.HasFlag(CornerRadiusPosition.TopLeft) ? r.TopLeft : 0;
+            double topRight = position.HasFlag(CornerRadiusPosition.TopRight) ? r.TopRight : 0;
+            double bottomLeft = position.HasFlag(CornerRadiusPosition.BottomLeft) ? r.BottomLeft : 0;
+            double bottomRight = position.HasFlag(CornerRadiusPosition.BottomRight) ? r.BottomRight : 0;
             return new CornerRadius(topLeft, topRight, bottomRight, bottomLeft);
         }
         return AvaloniaProperty.UnsetValue;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
@@ -70,7 +64,7 @@ public class CornerRadiusExcludeConverter : IValueConverter
     {
         _position = position;
     }
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is CornerRadius r)
         {
@@ -83,7 +77,7 @@ public class CornerRadiusExcludeConverter : IValueConverter
         return AvaloniaProperty.UnsetValue;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/src/Ursa/Converters/DivideByTwoConverter.cs b/src/Ursa/Converters/DivideByTwoConverter.cs
index 1fc2c74..15c2aa3 100644
--- a/src/Ursa/Converters/DivideByTwoConverter.cs
+++ b/src/Ursa/Converters/DivideByTwoConverter.cs
@@ -15,7 +15,7 @@ public class DivideByTwoConverter : IValueConverter
         return value;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/src/Ursa/Converters/ThicknessConverter.cs b/src/Ursa/Converters/ThicknessConverter.cs
index 6073cf0..17616b0 100644
--- a/src/Ursa/Converters/ThicknessConverter.cs
+++ b/src/Ursa/Converters/ThicknessConverter.cs
@@ -17,7 +17,7 @@ public enum ThicknessPosition
     BottomRight = 12,
 }
 
-public class ThicknessExcludeConverter: IValueConverter
+public class ThicknessExcludeConverter(ThicknessPosition position) : IValueConverter
 {
     public static ThicknessExcludeConverter Left { get; } = new( ThicknessPosition.Left );
     public static ThicknessExcludeConverter Top { get; } = new( ThicknessPosition.Top );
@@ -28,33 +28,27 @@ public class ThicknessExcludeConverter: IValueConverter
     public static ThicknessExcludeConverter BottomLeft { get; } = new( ThicknessPosition.BottomLeft );
     public static ThicknessExcludeConverter BottomRight { get; } = new( ThicknessPosition.BottomRight );
 
-    private readonly ThicknessPosition _position;
-    public ThicknessExcludeConverter(ThicknessPosition position)
-    {
-        _position = position;
-    }
-    
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Thickness t)
         {
-            double left = _position.HasFlag(ThicknessPosition.Left) ?  0d: t.Left;
-            double top = _position.HasFlag(ThicknessPosition.Top) ? 0d : t.Top;
-            double right = _position.HasFlag(ThicknessPosition.Right) ? 0d : t.Right;
-            double bottom = _position.HasFlag(ThicknessPosition.Bottom) ? 0d : t.Bottom;
+            double left = position.HasFlag(ThicknessPosition.Left) ?  0d: t.Left;
+            double top = position.HasFlag(ThicknessPosition.Top) ? 0d : t.Top;
+            double right = position.HasFlag(ThicknessPosition.Right) ? 0d : t.Right;
+            double bottom = position.HasFlag(ThicknessPosition.Bottom) ? 0d : t.Bottom;
 
             return new Thickness(left, top, right, bottom);
         }
         return AvaloniaProperty.UnsetValue;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
 }
 
-public class ThicknessIncludeConverter: IValueConverter
+public class ThicknessIncludeConverter(ThicknessPosition position) : IValueConverter
 {
     public static ThicknessIncludeConverter Left { get; } = new( ThicknessPosition.Left );
     public static ThicknessIncludeConverter Top { get; } = new( ThicknessPosition.Top );
@@ -65,26 +59,20 @@ public class ThicknessIncludeConverter: IValueConverter
     public static ThicknessIncludeConverter BottomLeft { get; } = new( ThicknessPosition.BottomLeft );
     public static ThicknessIncludeConverter BottomRight { get; } = new( ThicknessPosition.BottomRight );
 
-    private readonly ThicknessPosition _position;
-    public ThicknessIncludeConverter(ThicknessPosition position)
-    {
-        _position = position;
-    }
-    
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         if (value is Thickness t)
         {
-            var left = _position.HasFlag(ThicknessPosition.Left) ? t.Left : 0d;
-            var top = _position.HasFlag(ThicknessPosition.Top) ? t.Top : 0d;
-            var right = _position.HasFlag(ThicknessPosition.Right) ? t.Right : 0d;
-            var bottom = _position.HasFlag(ThicknessPosition.Bottom) ? t.Bottom : 0d;
+            var left = position.HasFlag(ThicknessPosition.Left) ? t.Left : 0d;
+            var top = position.HasFlag(ThicknessPosition.Top) ? t.Top : 0d;
+            var right = position.HasFlag(ThicknessPosition.Right) ? t.Right : 0d;
+            var bottom = position.HasFlag(ThicknessPosition.Bottom) ? t.Bottom : 0d;
             return new Thickness(left, top, right, bottom);
         }
         return AvaloniaProperty.UnsetValue;
     }
 
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
     {
         throw new NotImplementedException();
     }
diff --git a/src/Ursa/Windows/UrsaWindow.cs b/src/Ursa/Windows/UrsaWindow.cs
index 4532fd8..a23ea2b 100644
--- a/src/Ursa/Windows/UrsaWindow.cs
+++ b/src/Ursa/Windows/UrsaWindow.cs
@@ -1,6 +1,5 @@
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Platform;
 
 namespace Ursa.Controls;