Wpf Render Thread Failure Exception
In My Application, I Have a Task Which Runs in the Background to Perform a Long-Running Job. the User Can Cancel the Job Anytime by Clicking Stop Button. the...
In my application, I have a task which runs in the background to perform a long-running job. The user can cancel the job anytime by clicking Stop button. The implementation is as belows:
private CancellationTokenSource m_tokenSource;
private void onStop()
{
m_tokenSource.Cancel();
}
private void onStart()
{
m_tokenSource = new CancellationTokenSource();
AsyncDoingJob();
}
private async void AsyncDoingJob()
{
await Task.Run(() =>
{
for (int imgIdx = 0; imgIdx < m_ListImageFiles.Count; imgIdx++)
{
if (m_tokenSource.IsCancellationRequested) // Check if the user clicks Stop button
{
return;
}
byte[] imageData = File.ReadAllBytes(m_ListImageFiles[imgIdx]); // Load image in background
Application.Current.Dispatcher.Invoke(() =>
{
m_model.Image = CreateImage(imageData);
m_model.Image.Freeze();
MyImage = m_model.Image; // This calls NotifyPropertyChanged() to update the image on GUI
}
// Access to m_model.Image for some reason
}
}, m_tokenSource.Token);
}
The problem: Sometimes, while the job is being performed, GUI stop updating (hanging). And if I try to manipulate the GUI, an exception happens: System.Runtime.InteropServices.COMException: UCEERR_RENDERTHREADFAILURE (Exception from HRESULT: 0x88980406)
I found a similar problem reported here: WPF render thread failures
Do you know what it is and how to fix this? Is there anything wrong with my source code?
2 Answers
I can't tell why you get that error. You may however try an implementation like this:
private bool continueLoading;
private void OnStop()
{
continueLoading = false;
}
private async Task OnStart()
{
continueLoading = true;
await LoadImagesAsync(m_ListImageFiles);
}
private async Task LoadImagesAsync(IEnumerable<string> imageFiles)
{
foreach (var imageFile in imageFiles)
{
if (!continueLoading)
{
break;
}
Image = await LoadImageAsync(imageFile); // assignment in UI thread
// do more async calls here if necessary
}
}
private static Task<ImageSource> LoadImageAsync(string fileName)
{
return Task.Run(() =>
{
using (var stream = File.OpenRead(fileName))
{
return LoadImage(stream);
}
});
}
private static ImageSource LoadImage(Stream stream)
{
return BitmapFrame.Create(
stream, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
// Alternative:
//
// var bitmapImage = new BitmapImage();
// bitmapImage.BeginInit();
// bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
// bitmapImage.StreamSource = stream;
// bitmapImage.EndInit();
// bitmapImage.Freeze();
// return bitmapImage;
}
After migrating a large WPF application from the .NET Framework to .NET 7, for some users the application began to crash with this exception.
System.Runtime.InteropServices.COMException UCEERR_RENDERTHREADFAILURE (0x88980406)
The reason for the exception is not clear, but disabling hardware graphics acceleration worked for me.
using System.Windows.Media;
RenderOptions.ProcessRenderMode = System.Windows.Interop.RenderMode.SoftwareOnly;
P.S. See the document from Microsoft for a discussion of this exception.
David Miller brings 15 years of experience in global economics, personal finance strategy, and market dynamics. He specializes in turning complex economic trends into actionable insights for everyday readers.
