private static void OnUriSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { DeepZoomImageTileSource deepZoomImageTileSource = (DeepZoomImageTileSource)d; Uri oldUriSource = (Uri)e.OldValue; Uri uriSource = deepZoomImageTileSource.UriSource; deepZoomImageTileSource.OnUriSourceChanged(oldUriSource, uriSource); }