Question

I’ve been trying to Serialize and Deserialize BitmapImages. I’ve been using methods which supposedly works which I found in this thread: error in my byte[] to WPF BitmapImage conversion?

Just to iterate what is going on, here is part of my Serialization code:

using (MemoryStream ms = new MemoryStream())
                {
                    // This is a BitmapImage fetched from a dictionary.
                    BitmapImage image = kvp.Value; 

                    PngBitmapEncoder encoder = new PngBitmapEncoder();
                    encoder.Frames.Add(BitmapFrame.Create(image));
                    encoder.Save(ms);

                    byte[] buffer = ms.GetBuffer();

                    // Here I'm adding the byte[] array to SerializationInfo
                    info.AddValue((int)kvp.Key + "", buffer);
                }

And here is the deserialization code:

// While iterating over SerializationInfo in the deserialization
// constructor I pull the byte[] array out of an 
// SerializationEntry
using (MemoryStream ms = new MemoryStream(entry.Value as byte[]))
                    {
                        ms.Position = 0;

                        BitmapImage image = new BitmapImage();
                        image.BeginInit();
                        image.StreamSource = ms;
                        image.EndInit();

                        // Adding the timeframe-key and image back into the dictionary
                        CapturedTrades.Add(timeframe, image);
                    }

Also, I’m not sure if it matters but earlier when I populated my dictionary I encoded Bitmaps with PngBitmapEncoder to get them into BitmapImages. So not sure if double-encoding has something to do with it. Here’s the method that does that:

// Just to clarify this is done before the BitmapImages are added to the
// dictionary that they are stored in above.
private BitmapImage BitmapConverter(Bitmap image)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                BitmapImage bImg = new BitmapImage();
                bImg.BeginInit();
                bImg.StreamSource = new MemoryStream(ms.ToArray());
                bImg.EndInit();
                ms.Close();

                return bImg;
            }
        }

So the problem is, serialization and deserialization works fine. No errors, and the dictionary has entries with what seems to be BitmapImages, however their width/height and
some other properties are all set to ‘0’ when I look at them in debugging-mode. And of course, nothing is shown when I try to display the images.

So any ideas as to why they aren’t properly deserialized?

Thanks!

Answer 1

1) You should not dispose MemoryStream, used from image initializing. Remove using in this line

using (MemoryStream ms = new MemoryStream(entry.Value as byte[]))

2) After

encoder.Save(ms);

Try adding

ms.Seek(SeekOrigin.Begin, 0);
ms.ToArray();