Question

why can I not add a wpfImage of type BitmapImage/BitmapSource/ImageSource to a Resource file.

Yes its not serializeable… So how can I workaround this? I need to put my bitmapImages in a Resource file with key/value access programatically.

   using (ResXResourceWriter writer = new ResXResourceWriter("TBM.Resource"))
   {
         writer.AddResource(fileExtension, wpfImage);
         writer.Generate();
    }

Answer 1

Resx files were not designed to be used with WPF images. They work fine with GDI images though, so you can save the image to a System.Drawing.Bitmap, and add it to the resource file.

var encoder = new PngBitmapEncoder();
using (var stream = new MemoryStream())
{
    // Write the WPF image to the stream
    encoder.Frames.Add(BitmapFrame.Create(wpfImage));
    encoder.Save(stream);

    // Rewind the stream
    stream.Position = 0;

    // Read the stream to a GDI image
    var bitmap = (System.Drawing.Bitmap)System.Drawing.Image.FromStream(stream);

    // Add the GDI image to the resource file
    writer.AddResource(fileExtension, bitmap);
}