private void Window_Loaded(object sender, RoutedEventArgs e)
 {
     LoginWindow loginWindow = new LoginWindow(this.HandleSuccessLogin);
     this.MainFrame.Children.Add(loginWindow);
     loginWindow.IsModal = true;
     loginWindow.Show();
     loginWindow.BringToFront();
 }
 private void ShowLoginWindow()
 {
     LoginWindow loginWindow = new LoginWindow(this.HandleSuccessLogin);
     this.MainFrame.Children.Add(loginWindow);
     loginWindow.IsModal = true;
     loginWindow.Show();
     loginWindow.BringToFront();
 }