Fix for the following:

Warning CA1001 Type 'MainWindow' owns disposable field(s) '_firstDeleteTimer' but is not disposable PowerLauncher C:\Repos\PowerToys\src\modules\launcher\PowerLauncher\MainWindow.xaml.cs

    Warning CA1816 Change App.Dispose() to call GC.SuppressFinalize(object). This will prevent derived types that introduce a finalizer from needing to re-implement 'IDisposable' to call it. PowerLauncher C:\Repos\PowerToys\src\modules\launcher\PowerLauncher\App.xaml.cs

src/modules/launcher/PowerLauncher/App.xaml.cs

@@ -29,6 +29,7 @@ namespace PowerLauncher
         private static int _powerToysPid;
         private Settings _settings;
         private MainViewModel _mainVM;
+        private MainWindow _mainWindow;
         private SettingWindowViewModel _settingsVM;
         private readonly Alphabet _alphabet = new Alphabet();
         private StringMatcher _stringMatcher;
@@ -78,11 +79,11 @@ namespace PowerLauncher
                 ThemeManager themeManager = new ThemeManager(this);               
                 PluginManager.LoadPlugins(_settings.PluginSettings);
                 _mainVM = new MainViewModel(_settings);
-                var window = new MainWindow(_settings, _mainVM);
+                _mainWindow = new MainWindow(_settings, _mainVM);
                 API = new PublicAPIInstance(_settingsVM, _mainVM, _alphabet);
                 PluginManager.InitializePlugins(API);
 
-                Current.MainWindow = window;
+                Current.MainWindow = _mainWindow;
                 Current.MainWindow.Title = Constant.ExeFileName;
 
                 // happlebao todo temp fix for instance code logic
@@ -161,20 +162,40 @@ namespace PowerLauncher
             AppDomain.CurrentDomain.UnhandledException += ErrorReporting.UnhandledExceptionHandle;
         }
 
-        public void Dispose()
-        {
-            // if sessionending is called, exit proverbially be called when log off / shutdown
-            // but if sessionending is not called, exit won't be called when log off / shutdown
-            if (!_disposed)
-            {
-                API.SaveAppAllSettings();
-                _disposed = true;
-            }
-        }
-
         public void OnSecondAppStarted()
         {
             Current.MainWindow.Visibility = Visibility.Visible;
         }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!_disposed)
+            {
+                if (disposing)
+                {
+                    _mainWindow.Dispose();
+                    API.SaveAppAllSettings();
+                    _disposed = true;
+                }
+
+                // TODO: free unmanaged resources (unmanaged objects) and override finalizer
+                // TODO: set large fields to null
+                _disposed = true;
+            }
+        }
+
+        // // TODO: override finalizer only if 'Dispose(bool disposing)' has code to free unmanaged resources
+        // ~App()
+        // {
+        //     // 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);
+        }
     }
 }

src/modules/launcher/PowerLauncher/MainWindow.xaml.cs

@@ -16,9 +16,10 @@ using System.Timers;
 using Microsoft.PowerLauncher.Telemetry;
 using Microsoft.PowerToys.Telemetry;
 
+
 namespace PowerLauncher
 {
-    public partial class MainWindow
+    public partial class MainWindow : IDisposable
     {
 
         #region Private Fields
@@ -268,6 +269,8 @@ namespace PowerLauncher
 
         private const int millisecondsToWait = 100;
         private static DateTime s_lastTimeOfTyping;
+        private bool disposedValue = false;
+
         private string ListView_FirstItem(String input)
         {
             if (!string.IsNullOrEmpty(input))
@@ -356,5 +359,34 @@ namespace PowerLauncher
         {
             Hide();
         }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!disposedValue)
+            {
+                if (disposing)
+                {
+                    _firstDeleteTimer.Dispose();
+                }
+
+                // TODO: free unmanaged resources (unmanaged objects) and override finalizer
+                // TODO: set large fields to null
+                disposedValue = true;
+            }
+        }
+
+        // // TODO: override finalizer only if 'Dispose(bool disposing)' has code to free unmanaged resources
+        // ~MainWindow()
+        // {
+        //     // 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);
+        }
     }
 }