//TODO: implement
//- PROGRESS BAR: injecting new Progress<int>(p => pbDownloadProgress.Value = p)
//- CANCELLATION ACTION: 'Convert' button changes a label("Cancel") and to CLICL is attached a RoutedEventHandler CancelConversion_Click() while TASK in progress
private void BtnConvertImage_Click(object sender, RoutedEventArgs e)
{
string nano, mili;
bool isHighResolution;
btnLoad.IsEnabled = false;
OperationsTimer.StartMeasurement();
var originalImage = (imgPhotoOrginal.Source as BitmapImage);
try
{
if (cbAsync.IsChecked == false)
{
imgPhotoConverted.Source = originalImage.ToBitmap().ToGrayscale(cts.Token).ToBitmapImage();
}
else
{
cts.CancelAfter(TimeSpan.FromSeconds(1));
//BitmapImage result = await Task.Run(() => {
// return originalImage.ToBitmap().ToGrayscale(cts.Token).ToBitmapImage();
//});
//imgPhotoConverted.Source = result;
//<!--!> BELOW is other 'working' implementation using ThreadPool in scenario when TASK(Promise) is returned from diff Thread/Context - it is less elegant(requires a delegation of following tasks into UI SynchronizationContext) but I think it is worth mentioning:
var sc = SynchronizationContext.Current;
ThreadPool.QueueUserWorkItem(async delegate
{
// work on ThreadPool
var cts = new CancellationTokenSource();
BitmapImage result = await ImageProcessing.GreyscaleAsync(orginalImage, cts.Token);
result.Freeze();
sc.Post(delegate
{
// work on the original context (UI)
imgPhotoConverted.Source = result;
cts.Cancel();
(nano, mili, isHighResolution) = OperationsTimer.StopMeasurement();
lblPerformance.Content = String.Concat("Total time: ", String.Concat(nano, " ns | "), String.Concat(mili, " ms | "), String.Concat("HiRes: ", isHighResolution ? "Enabled" : "Disabled"));
}, null);
});
