feat: add new Toast.

demo/Ursa.Demo/ViewModels/ToastDemoViewModel.cs

@@ -0,0 +1,57 @@
+using System;
+using Avalonia.Controls.Notifications;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Ursa.Controls;
+
+namespace Ursa.Demo.ViewModels;
+
+public partial class ToastDemoViewModel : ObservableObject
+{
+    public WindowToastManager? ToastManager { get; set; }
+
+    [RelayCommand]
+    public void ShowNormal(object obj)
+    {
+        if (obj is string s)
+        {
+            Enum.TryParse<NotificationType>(s, out var notificationType);
+            ToastManager?.Show(
+                new Toast("This is message"),
+                type: notificationType);
+        }
+
+        // ToastManager?.Show(new ToastDemoViewModel
+        // {
+        //     Content = "This is message",
+        //     ToastManager = ToastManager
+        // });
+    }
+
+    [RelayCommand]
+    public void ShowLight(object obj)
+    {
+        if (obj is string s)
+        {
+            Enum.TryParse<NotificationType>(s, out var notificationType);
+            ToastManager?.Show(
+                new Toast("This is message"),
+                type: notificationType,
+                classes: ["Light"]);
+        }
+    }
+
+    public string? Content { get; set; }
+
+    [RelayCommand]
+    public void YesCommand()
+    {
+        ToastManager?.Show(new Toast("Yes!"));
+    }
+
+    [RelayCommand]
+    public void NoCommand()
+    {
+        ToastManager?.Show(new Toast("No!"));
+    }
+}