XAML-Map-Control/MapControl/MapImageLayer.Silverlight.WinRT.cs

// XAML Map Control - http://xamlmapcontrol.codeplex.com/
// Copyright © 2014 Clemens Fischer
// Licensed under the Microsoft Public License (Ms-PL)

#if NETFX_CORE
using Windows.UI.Xaml;
using Windows.UI.Xaml.Media.Imaging;
#else
using System.Windows;
using System.Windows.Media.Imaging;
using System.Windows.Threading;
#endif

namespace MapControl
{
    public partial class MapImageLayer
    {
        private readonly DispatcherTimer updateTimer = new DispatcherTimer();

        private void AddDownloadEventHandlers(BitmapSource bitmap)
        {
            var bitmapImage = bitmap as BitmapImage;

            if (bitmapImage != null)
            {
                bitmapImage.ImageOpened += BitmapImageOpened;
                bitmapImage.ImageFailed += BitmapImageFailed;
            }
            else
            {
                BlendImages();
            }
        }

        private void BitmapImageOpened(object sender, RoutedEventArgs e)
        {
            var bitmap = (BitmapImage)sender;

            bitmap.ImageOpened -= BitmapImageOpened;
            bitmap.ImageFailed -= BitmapImageFailed;

            BlendImages();
        }

        private void BitmapImageFailed(object sender, ExceptionRoutedEventArgs e)
        {
            var bitmap = (BitmapImage)sender;

            bitmap.ImageOpened -= BitmapImageOpened;
            bitmap.ImageFailed -= BitmapImageFailed;

            ((MapImage)Children[currentImageIndex]).Source = null;
            BlendImages();
        }
    }
}