feat: add TryGetXXManager to WindowXXManager.

src/Ursa/Controls/Notification/WindowNotificationManager.cs

@@ -5,6 +5,7 @@ using Avalonia.Controls.Notifications;
 using Avalonia.Controls.Primitives;
 using Avalonia.Layout;
 using Avalonia.Threading;
+using Avalonia.VisualTree;
 
 namespace Ursa.Controls;
 
@@ -69,6 +70,12 @@ public class WindowNotificationManager : WindowMessageManager, INotificationMana
         VerticalAlignmentProperty.OverrideDefaultValue<WindowNotificationManager>(VerticalAlignment.Stretch);
     }
 
+    public static bool TryGetNotificationManager(Visual? visual, out WindowNotificationManager? manager)
+    {
+        manager = visual?.FindDescendantOfType<WindowNotificationManager>();
+        return manager is not null;
+    }
+
     /// <inheritdoc/>
     public void Show(INotification content)
     {

src/Ursa/Controls/NotificationShared/WindowMessageManager.cs

@@ -84,6 +84,12 @@ public abstract class WindowMessageManager : TemplatedControl
         }
     }
 
+    public static bool TryGetMessageManager(Visual? visual, out WindowMessageManager? manager)
+    {
+        manager = visual?.FindDescendantOfType<WindowMessageManager>();
+        return manager is not null;
+    }
+
     protected void TopLevelOnTemplateApplied(object? sender, TemplateAppliedEventArgs e)
     {
         if (Parent is AdornerLayer adornerLayer)

src/Ursa/Controls/Toast/WindowToastManager.cs

@@ -1,7 +1,9 @@
-using Avalonia.Controls;
+using Avalonia;
+using Avalonia.Controls;
 using Avalonia.Controls.Notifications;
 using Avalonia.Controls.Primitives;
 using Avalonia.Threading;
+using Avalonia.VisualTree;
 
 namespace Ursa.Controls;
 
@@ -33,6 +35,12 @@ public class WindowToastManager : WindowMessageManager, IToastManager
     {
     }
 
+    public static bool TryGetToastManager(Visual? visual, out WindowToastManager? manager)
+    {
+        manager = visual?.FindDescendantOfType<WindowToastManager>();
+        return manager is not null;
+    }
+
     /// <inheritdoc/>
     public void Show(IToast content)
     {