private async Task LoadVirtualBitmap()
{
if (virtualBitmap != null)
{
virtualBitmap.Dispose();
virtualBitmap = null;
}
LoadedImageInfo = "";
NotifyBitmapChanged();
virtualBitmap = await CanvasVirtualBitmap.LoadAsync(ImageVirtualControl.Device, imageStream, virtualBitmapOptions);
if (ImageVirtualControl == null)
{
// This can happen if the page is unloaded while LoadAsync is running
return;
}
var size = virtualBitmap.Size;
ImageVirtualControl.Width = size.Width;
ImageVirtualControl.Height = size.Height;
ImageVirtualControl.Invalidate();
LoadedImageInfo = string.Format("{0}x{1} image, is {2}CachedOnDemand",
size.Width, size.Height, virtualBitmap.IsCachedOnDemand ? "" : "not ");
NotifyBitmapChanged();
}
private void Control_Unloaded(object sender, RoutedEventArgs e)
{
IOGraph.RemoveFromVisualTree();
ImageVirtualControl.RemoveFromVisualTree();
IOGraph = null;
ImageVirtualControl = null;
}
private void ImageVirtualControl_RegionsInvalidated(CanvasVirtualControl sender, CanvasRegionsInvalidatedEventArgs args)
{
foreach (var region in args.InvalidatedRegions)
{
using (var ds = ImageVirtualControl.CreateDrawingSession(region))
{
if (virtualBitmap != null)
{
ds.DrawImage(virtualBitmap, region, region);
}
}
}
}
