Question

I have a class I serialize to a file, ie. myfile01.myfile. I’m using binary serialization (not xml).

In version 1 of this class, there was a field ‘ColoredFont’. This is a class that contains a Font and a Color.

In version 2 of the class, the class ColoredFont was changed, and the ‘Font’ field was replaced by ‘SerializableFont’.

Now the problem: when i want to open version 1 files, I get an error :

 Object of type 'System.Drawing.Font' cannot be converted to 
 type 'Project.SerializableFont'.

I already use a custom serialization binder

public class Binder : SerializationBinder {

    public override Type BindToType(string assemblyName, string typeName) {
        Type tyType = null;
        string sShortAssemblyName = assemblyName.Split(',')[0];
        Assembly[] ayAssemblies = AppDomain.CurrentDomain.GetAssemblies();
        if (sShortAssemblyName.ToLower() == "project"
            || sShortAssemblyName == "SoftwareV_3.0"  )
        {
            sShortAssemblyName = "SoftwareV_4.0";
        }
           foreach (Assembly ayAssembly in ayAssemblies) {
               if (sShortAssemblyName == ayAssembly.FullName.Split(',')[0]) {
                tyType = ayAssembly.GetType(typeName);
                break;
            }
        }
        return tyType;
    }
}

How I can tell the deserialization to convert System.Drawing.Font to SerializableFont ??

Answer 1

Try this for the ColoredFont class :

[Serializable]
public class ColoredFont : ISerializable
{
    public SerializableFont SerializableFont;
    public Color Color;

    private ColoredFont(SerializationInfo info, StreamingContext context)
    {
        Color = (Color)info.GetValue("Color", typeof(Color));
        try
        {
            SerializableFont = (SerializableFont)info.GetValue("SerializableFont", typeof(SerializableFont));
        }
        catch (SerializationException serEx)
        {
            Font f = (Font)info.GetValue("Font", typeof(Font));
            // do something to initialize SerializedFont from 'f'
        }

    }

    #region ISerializable Members

    public void GetObjectData(SerializationInfo info, StreamingContext context)
    {
        info.AddValue("SerializableFont", SerializableFont);
        info.AddValue("Color", Color);
    }

    #endregion
}