implement trayicon lifetime management.

src/Avalonia.Controls/Platform/ITrayIconImpl.cs

@@ -6,7 +6,7 @@ using Avalonia.Controls.Platform;
 
 namespace Avalonia.Platform
 {
-    public interface ITrayIconImpl
+    public interface ITrayIconImpl : IDisposable
     {
         /// <summary>
         /// Sets the icon of this tray icon.

src/Avalonia.Controls/TrayIcon.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using Avalonia.Collections;
+using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Controls.Platform;
 using Avalonia.Platform;
 
@@ -12,7 +13,7 @@ namespace Avalonia.Controls
     {
     }
 
-    public class TrayIcon : AvaloniaObject, IDataContextProvider, INativeMenuExporterProvider
+    public class TrayIcon : AvaloniaObject, IDataContextProvider, INativeMenuExporterProvider, IDisposable
     {
         private readonly ITrayIconImpl _impl;
 
@@ -44,6 +45,21 @@ namespace Avalonia.Controls
                     }
                 }
             });
+
+            if (Application.Current.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime lifetime)
+            {
+                lifetime.Exit += Lifetime_Exit;
+            }
+        }
+
+        private static void Lifetime_Exit(object sender, ControlledApplicationLifetimeExitEventArgs e)
+        {
+            var trayIcons = GetTrayIcons(Application.Current);
+
+            foreach(var icon in trayIcons)
+            {
+                icon.Dispose();
+            }
         }
 
         private static void Icons_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
@@ -84,6 +100,7 @@ namespace Avalonia.Controls
         /// </summary>
         public static readonly StyledProperty<bool> IsVisibleProperty =
             Visual.IsVisibleProperty.AddOwner<TrayIcon>();
+        private bool _disposedValue;
 
         public static void SetTrayIcons(AvaloniaObject o, TrayIcons trayIcons) => o.SetValue(TrayIconsProperty, trayIcons);
 
@@ -160,5 +177,7 @@ namespace Avalonia.Controls
                 _impl.SetToolTipText(change.NewValue.GetValueOrDefault<string?>());
             }
         }
+
+        public void Dispose() => _impl.Dispose();
     }
 }

src/Avalonia.DesignerSupport/Remote/TrayIconStub.cs

@@ -13,6 +13,11 @@ namespace Avalonia.DesignerSupport.Remote
 
         public INativeMenuExporter MenuExporter => throw new NotImplementedException();
 
+        public void Dispose()
+        {
+            throw new NotImplementedException();
+        }
+
         public void SetIcon(IWindowIconImpl icon)
         {   
         }

src/Windows/Avalonia.Win32/TrayIconImpl.cs

@@ -25,6 +25,7 @@ namespace Avalonia.Win32
         private readonly Win32NativeToManagedMenuExporter _exporter;
 
         private static Dictionary<int, TrayIconImpl> s_trayIcons = new Dictionary<int, TrayIconImpl>();
+        private bool _disposedValue;
 
         public INativeMenuExporter MenuExporter => _exporter;
 
@@ -45,12 +46,6 @@ namespace Avalonia.Win32
             s_trayIcons.Add(_uniqueId, this);
         }
 
-
-        ~TrayIconImpl()
-        {
-            UpdateIcon(false);
-        }
-
         public void SetIcon(IWindowIconImpl? icon)
         {
             _icon = icon as IconImpl;
@@ -258,5 +253,28 @@ namespace Avalonia.Win32
                 public virtual double Scaling => _hiddenWindow.Screens.Primary.PixelDensity;
             }
         }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!_disposedValue)
+            {
+                UpdateIcon(true);
+
+                _disposedValue = true;
+            }
+        }
+
+         ~TrayIconImpl()
+         {
+             // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+             Dispose(disposing: false);
+         }
+
+        public void Dispose()
+        {
+            // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+            Dispose(disposing: true);
+            GC.SuppressFinalize(this);
+        }
     }
 }