private void PageUnloaded(object sender, RoutedEventArgs e) {
     if (this._Svc != null) {
         _Svc.Dispose();
         _Svc = null;
     }
     VM.VideoService = null;
 }
        public NewVideo() {
            InitializeComponent();

            _Svc = new VideoService(this.viewfinderRectangle, this.videoPlayer);

            _record = new CommandButtonAdapter(ApplicationBar.Buttons[0] as IApplicationBarIconButton, _Svc.Record);
            _play = new CommandButtonAdapter(ApplicationBar.Buttons[1] as IApplicationBarIconButton, _Svc.Play);
            _stop = new CommandButtonAdapter(ApplicationBar.Buttons[2] as IApplicationBarIconButton, _Svc.Stop);
            _save = new SaveDeleteButton(
                this.ApplicationBar,
                VM);


            VM.VideoService = _Svc as IVideoService;
        }