Add exit function to the main interface for Desktop

v2rayN/ServiceLib/ViewModels/MainWindowViewModel.cs

@@ -52,6 +52,8 @@ namespace ServiceLib.ViewModels
 
         public ReactiveCommand<Unit, Unit> ReloadCmd { get; }
 
+        public ReactiveCommand<Unit, Unit> ExitCmd { get; }
+
         [Reactive]
         public bool BlReloadEnabled { get; set; }
 
@@ -187,6 +189,11 @@ namespace ServiceLib.ViewModels
                 await Reload();
             });
 
+            ExitCmd = ReactiveCommand.CreateFromTask(async () =>
+            {
+                await Exit();
+            });
+
             RegionalPresetDefaultCmd = ReactiveCommand.CreateFromTask(async () =>
             {
                 await ApplyRegionalPreset(EPresetType.Default);
@@ -588,6 +595,16 @@ namespace ServiceLib.ViewModels
             }
         }
 
+        private async Task Exit()
+        {
+            if (await _updateView?.Invoke(EViewAction.ShowYesNo, null) == false)
+            {
+                return;
+            }
+
+            await MyAppExitAsync(false);
+        }
+
         #endregion core job
 
         #region Presets