dotnet/wpf · error · ArgumentException

SR.Image_NoDecodeFrames

Error message

SR.Image_NoDecodeFrames

What it means

FinalizeCreation decodes the downloaded/opened bitmap into a frame. WPF throws ArgumentException with SR.Image_NoDecodeFrames when the decoder produced zero frames, meaning the image source yielded no decodable image data. The bitmap cannot be displayed, so creation is aborted.

Solutions

  1. Verify the image source is a complete, valid image file (open it in an image viewer or check magic bytes) before assigning it to BitmapImage
  2. Check the HTTP response status and content type before saving/downloading to a stream used by BitmapImage
  3. Wrap EndInit in try/catch for ArgumentException and fall back to a placeholder image or retry the download
  4. Confirm the required WIC codec for the format is installed on the machine

Example fix

// before
var bmp = new BitmapImage();
bmp.BeginInit();
bmp.UriSource = new Uri(url);
bmp.EndInit(); // throws if decoder yields 0 frames
// after
var bmp = new BitmapImage();
bmp.BeginInit();
bmp.UriSource = new Uri(url);
try { bmp.EndInit(); }
catch (ArgumentException) { bmp = CreatePlaceholderImage(); }
Defensive patterns

Strategy: try-catch

Validate before calling

// validate before decode
static bool LooksLikeImage(byte[] data) =>
    data != null && data.Length > 0 &&
    (data.Length >= 8 && data[0]==0x89 && data[1]==(byte)'P' ||  // PNG
     data[0]==0xFF && data[1]==0xD8 ||                            // JPEG
     data[0]==(byte)'G' && data[1]==(byte)'I' && data[2]==(byte)'F'); // GIF

Try / catch

try { img.EndInit(); }
catch (ArgumentException ex) when (ex.Message.Contains("NoDecodeFrames") || ex.ParamName == null)
{
    logger.LogWarning(ex, "Image decoded to 0 frames: {Uri}", uri);
    imageControl.Source = CreatePlaceholder();
}

Prevention

When it happens

Trigger: Calling EndInit() on a BitmapImage (or the download completing via OnDownloadCompleted) when the underlying stream/URI contains no decodable image frames — e.g. a zero-byte file, truncated download, HTML error page saved as .png, or a corrupt/unsupported image format.

Common situations: Server returns a 404/500 HTML page where an image was expected; network interrupted mid-download; file corrupted on disk; codec not installed for the format (e.g. HD Photo/WDP); empty placeholder files generated by a build or upload pipeline.

Understand the failure class

Background: EmptyResultError / "no results found": when an API or scraper succeeds but returns zero rows — this error's family across 9 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/825884f7481b506c. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Imaging/BitmapImage.cs:381

                    decoder.DownloadCompleted += OnDownloadCompleted;
                    decoder.DownloadFailed += OnDownloadFailed;
                }
                else
                {
                    Debug.Assert(decoder.SyncObject != null);
                }
            }
            else
            {
                // We already had a decoder, meaning we were downloading
                Debug.Assert(!_decoder.IsDownloading);
                decoder = _decoder;
                _decoder = null;
            }

            if (decoder.Frames.Count == 0)
            {
                throw new System.ArgumentException(SR.Image_NoDecodeFrames);
            }

            BitmapFrame frame = decoder.Frames[0];
            BitmapSource source = frame;

            Int32Rect sourceRect = SourceRect;

            if (sourceRect.X == 0 && sourceRect.Y == 0 &&
                sourceRect.Width == source.PixelWidth &&
                sourceRect.Height == source.PixelHeight)
            {
                sourceRect = Int32Rect.Empty;
            }

            if (!sourceRect.IsEmpty)
            {
                CroppedBitmap croppedSource = new CroppedBitmap();
                croppedSource.BeginInit();

View on GitHub (pinned to 81131a70a4)