private async Task UpdateSourceAsync()
{
_imageDecoder?.Dispose();
_initializationCancellationTokenSource?.Cancel();
_image.Source = null;
this.PixelHeight = 0d;
this.PixelWidth = 0d;
Interlocked.Exchange(ref _imageDecoder, null);
if (UriSource != null)
{
var uriSource = UriSource;
var cancellationTokenSource = new CancellationTokenSource();
_initializationCancellationTokenSource = cancellationTokenSource;
try
{
this.OnLoadingStarted();
var imageSource = await LoadImageByUri(uriSource, cancellationTokenSource);
if (uriSource.Equals(UriSource))
{
_image.Source = imageSource;
}
else
{
//不处理此情况
}
this.OnLoadingCompleted(imageSource);
}
catch (TaskCanceledException)
{
// Task Canceled
}
catch (FileNotFoundException fnfex)
{
this.OnFail(fnfex);
}
catch (Exception ex)
{
this.OnFail(ex);
}
}
}