Serialize and Store an Image in an XML File

Question

Got a little bit of a problem. I have a program that builds an observable collection of Users. The User has a Firstname, Lastname, and Image. I can add the user to the obser

Answer 1

XmlSerializer can't serialize or deserialize the WPF image types like BitmapImage etc. It is however able to (de)serialize byte arrays. So you may add a byte[] ImageBuffer property to your Person class, which contains the binary image data. You would then also set the XmlIgnore attribute on the Image property to suppress its (de)serialization, and set XmlElement("Image") on the ImageBuffer properties to (de)serialize it as <Image>...</Image>.

public class User
{
    public string FirstName { get; set; }
    public string LastName { get; set; }

    [XmlIgnore]
    public BitmapSource Image { get; set; }

    [XmlElement("Image")]
    public byte[] ImageBuffer
    {
        get
        {
            byte[] imageBuffer = null;

            if (Image != null)
            {
                using (var stream = new MemoryStream())
                {
                    var encoder = new PngBitmapEncoder(); // or some other encoder
                    encoder.Frames.Add(BitmapFrame.Create(Image));
                    encoder.Save(stream);
                    imageBuffer = stream.ToArray();
                }
            }

            return imageBuffer;
        }
        set
        {
            if (value == null)
            {
                Image = null;
            }
            else
            {
                using (var stream = new MemoryStream(value))
                {
                    var decoder = BitmapDecoder.Create(stream,
                        BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
                    Image = decoder.Frames[0];
                }
            }
        }
    }
}

This approach has also been suggested for properties of type Bitmap in this answer.

Answer 2

You would base64 encode the image to convert it to a string and then write that into a CDATA section. See How do you serialize a string as CDATA using XmlSerializer?