void SlideshowView_Loaded(object sender, RoutedEventArgs e)
        {
            if (loader != null)
            {
                return;
            }

            ImageHost.Width     = ActualWidth;
            ImageHost.Height    = ActualHeight;
            loader              = new ImageLoader(allFilenames);
            loader.ImageLoaded += loader_ImageLoaded;
            loader.BeginLoad((int)ActualWidth, (int)ActualHeight);
            DoNavigateTo(0);
        }
        void SlideshowView_Loaded(object sender, RoutedEventArgs e)
        {
            if (loader != null)
                return;

            ImageHost.Width = ActualWidth;
            ImageHost.Height = ActualHeight;
            loader = new ImageLoader(allFilenames);
            loader.ImageLoaded += loader_ImageLoaded;
            loader.BeginLoad((int)ActualWidth, (int)ActualHeight);
            DoNavigateTo(0);
        }