private async void LoginButtonClick(object sender, RoutedEventArgs e) { var command = new Command() { Student = new StudentViewModel() { Login = loginTextBox.Text, Password = passwordTextBox.Password }, UserCommand = UserCommandServer.SignIn }; _connectService.SendCommand(command); var inBoxCommand = (await _connectService.ReadCommand()); if (inBoxCommand != null) { _connectService.Id = inBoxCommand.Id; if (inBoxCommand.IsSignIn) { TestMainWindow testMainWindow = new TestMainWindow(_connectService, _testServices); testMainWindow.Show(); Application.Current.MainWindow.Close(); } else { MessageBox.Show("Неверный логин или пароль"); } } else { MessageBox.Show("Сервер не отвечает"); } }