Remove Tabs when disconnect

ClientApp/ViewModels/MainWindowViewModel.cs

@@ -2,6 +2,7 @@
 using ClientApp.Utils;
 using System;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Text;
 
 namespace ClientApp.ViewModels
@@ -13,13 +14,22 @@ namespace ClientApp.ViewModels
         public ObservableObject SelectedViewModel { get; set; }
         public Client client { get; }
 
+        LoginViewModel loginViewModel;
+
         public MainWindowViewModel(Client client)
         {
             this.InfoModel = new Info();
             this.client = client;
-            LoginViewModel loginViewModel = new LoginViewModel(this);
+            loginViewModel = new LoginViewModel(this);
             SelectedViewModel = loginViewModel;
             this.client.SetLoginViewModel(loginViewModel);
+            App.Current.MainWindow.Closing += new CancelEventHandler(MainWindow_Closing);
+        }
+
+        void MainWindow_Closing(object sender, CancelEventArgs e)
+        {
+            this.client.sendMessage(DataParser.getDisconnectJson(loginViewModel.Username));
+
         }
 
     }