refactor: rewrite the way to quit app

Signed-off-by: leo <longshuang@msn.cn>

src/App.axaml.cs

@@ -230,15 +230,9 @@ namespace SourceGit
         public static void Quit(int exitCode)
         {
             if (Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
-            {
-                desktop.ShutdownMode = ShutdownMode.OnExplicitShutdown;
-                desktop.MainWindow?.Close();
                 desktop.Shutdown(exitCode);
-            }
             else
-            {
                 Environment.Exit(exitCode);
-            }
         }
         #endregion
 
@@ -478,7 +472,12 @@ namespace SourceGit
 
             _launcher = new ViewModels.Launcher(startupRepo);
             desktop.MainWindow = new Views.Launcher() { DataContext = _launcher };
-            desktop.ShutdownMode = ShutdownMode.OnMainWindowClose;
+            desktop.ShutdownMode = ShutdownMode.OnExplicitShutdown;
+            desktop.Exit += (_, _) =>
+            {
+                _ipcChannel?.Dispose();
+                _ipcChannel = null;
+            };
 
             _ipcChannel.MessageReceived += repo =>
             {
@@ -490,8 +489,6 @@ namespace SourceGit
                 });
             };
 
-            desktop.Exit += (_, _) => _ipcChannel.Dispose();
-
 #if !DISABLE_UPDATE_DETECTION
             if (pref.ShouldCheck4UpdateOnStartup())
                 Check4Update();

src/ViewModels/Launcher.cs

@@ -117,7 +117,7 @@ namespace SourceGit.ViewModels
             return false;
         }
 
-        public void Quit()
+        public void CloseAll()
         {
             _ignoreIndexChange = true;
 

src/Views/Launcher.axaml.cs

@@ -338,10 +338,17 @@ namespace SourceGit.Views
             base.OnClosing(e);
 
             if (!Design.IsDesignMode && DataContext is ViewModels.Launcher launcher)
-            {
+                launcher.CloseAll();
+        }
+
+        protected override void OnClosed(EventArgs e)
+        {
+            base.OnClosed(e);
+
+            if (!Design.IsDesignMode)
                 ViewModels.Preferences.Instance.Save();
-                launcher.Quit();
-            }
+
+            App.Quit(0);
         }
 
         private void OnPositionChanged(object sender, PixelPointEventArgs e)