VersionInfoWindow.xaml の相互作用ロジック
Inheritance: System.Windows.Window
 private void OnAbout(object sender, System.Windows.Input.ExecutedRoutedEventArgs e)
 {
     var dialog = new VersionInfoWindow {
     Owner = this,
     DataContext = ((PeerCastAppViewModel)DataContext).VersionInfo
       };
       dialog.ShowDialog();
 }
 private void VersionInfoButton_Click(object sender, RoutedEventArgs e)
 {
     var dialog = new VersionInfoWindow
       {
     Owner = Window.GetWindow(this),
     DataContext = ((MainViewModel)DataContext).VersionInfo
       };
       dialog.ShowDialog();
 }