public MainPage()
        {
            InitializeComponent();

            _faceDrawer = FaceDrawers.FirstOrDefault();
            DrawSelector.ItemsSource  = FaceDrawers;
            DrawSelector.SelectedItem = FaceDrawers.FirstOrDefault();

            NavigationCacheMode = NavigationCacheMode.Disabled;

            Application.Current.Suspending += Current_Suspending;
            Application.Current.Resuming   += Current_Resuming;
        }
 private void DrawSelector_SelectionChanged(object sender, SelectionChangedEventArgs e)
 {
     _faceDrawer = DrawSelector.SelectedItem as IFaceDrawer;
 }