From a02834717ff459100e7902862ab057629a8d4666 Mon Sep 17 00:00:00 2001
From: Emmanuel Hansen <emmausssss@gmail.com>
Date: Wed, 6 Dec 2023 06:25:59 +0000
Subject: [PATCH] unsubscribe android back handler when toplevel is disposed
 (#13831)

---
 .../Platform/AndroidSystemNavigationManager.cs      | 13 ++++++++++++-
 .../Platform/SkiaPlatform/TopLevelImpl.cs           |  3 ++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/Android/Avalonia.Android/Platform/AndroidSystemNavigationManager.cs b/src/Android/Avalonia.Android/Platform/AndroidSystemNavigationManager.cs
index 880918bebe..ec619fd0f3 100644
--- a/src/Android/Avalonia.Android/Platform/AndroidSystemNavigationManager.cs
+++ b/src/Android/Avalonia.Android/Platform/AndroidSystemNavigationManager.cs
@@ -6,8 +6,10 @@ using Avalonia.Platform;
 
 namespace Avalonia.Android.Platform
 {
-    internal class AndroidSystemNavigationManagerImpl : ISystemNavigationManagerImpl
+    internal class AndroidSystemNavigationManagerImpl : ISystemNavigationManagerImpl, IDisposable
     {
+        private readonly IActivityNavigationService? _navigationService;
+
         public event EventHandler<RoutedEventArgs>? BackRequested;
 
         public AndroidSystemNavigationManagerImpl(IActivityNavigationService? navigationService)
@@ -16,6 +18,7 @@ namespace Avalonia.Android.Platform
             {
                 navigationService.BackRequested += OnBackRequested;
             }
+            _navigationService = navigationService;
         }
 
         private void OnBackRequested(object? sender, AndroidBackRequestedEventArgs e)
@@ -26,5 +29,13 @@ namespace Avalonia.Android.Platform
 
             e.Handled = routedEventArgs.Handled;
         }
+
+        public void Dispose()
+        {
+            if (_navigationService != null)
+            {
+                _navigationService.BackRequested -= OnBackRequested;
+            }
+        }
     }
 }
diff --git a/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs b/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs
index 5d5f01db94..e9f9050af1 100644
--- a/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs
+++ b/src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs
@@ -45,7 +45,7 @@ namespace Avalonia.Android.Platform.SkiaPlatform
         private readonly AndroidInputMethod<ViewImpl> _textInputMethod;
         private readonly INativeControlHostImpl _nativeControlHost;
         private readonly IStorageProvider _storageProvider;
-        private readonly ISystemNavigationManagerImpl _systemNavigationManager;
+        private readonly AndroidSystemNavigationManagerImpl _systemNavigationManager;
         private readonly AndroidInsetsManager _insetsManager;
         private readonly ClipboardImpl _clipboard;
         private ViewImpl _view;
@@ -155,6 +155,7 @@ namespace Avalonia.Android.Platform.SkiaPlatform
         
         public virtual void Dispose()
         {
+            _systemNavigationManager.Dispose();
             _view.Dispose();
             _view = null;
         }