private async void SetAsWallPaperButton_OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e) { var trans = (IllustTransitioner)IllustBrowserContainer.Children[1]; var transitions = (IEnumerable <TransitionerSlide>)trans.IllustTransition.ItemsSource; var selectedIndex = transitions.ToList()[trans.IllustTransition.SelectedIndex]; var location = Path.Combine(AppContext.PermanentlyFolder, "wallpaper.bmp"); var wallPaper = new WallpaperManager(location, (BitmapSource)((IllustPresenter)selectedIndex.Content).ImgSource); await wallPaper.Execute(); }