增加IsShuttingDownFromTray标志位

SpineViewer/ViewModels/MainWindow/MainWindowViewModel.cs

@@ -29,6 +29,12 @@ namespace SpineViewer.ViewModels.MainWindow
 
         public string Title => $"SpineViewer - v{App.Version}";
 
+        /// <summary>
+        /// 指示是否通过托盘图标进行退出
+        /// </summary>
+        public bool IsShuttingDownFromTray => _isShuttingDownFromTray;
+        private bool _isShuttingDownFromTray;
+
         public bool? CloseToTray
         {
             get => _closeToTray;
@@ -101,8 +107,13 @@ namespace SpineViewer.ViewModels.MainWindow
         });
         private RelayCommand _cmd_SwitchWallpaperView;
 
-        public RelayCommand Cmd_Exit => _cmd_Exit ??= new(App.Current.Shutdown);
-        private RelayCommand? _cmd_Exit;
+        public RelayCommand Cmd_ExitFromTray => _cmd_ExitFromTray ??= new(() =>
+        {
+            _isShuttingDownFromTray = true;
+            OnPropertyChanged(nameof(IsShuttingDownFromTray));
+            App.Current.Shutdown();
+        });
+        private RelayCommand? _cmd_ExitFromTray;
 
         /// <summary>
         /// 打开工作区