Question

Given two app domain :
in the first, Library1 and CommonLibrary are loaded. In the second Library2 and CommonLibrary are loaded.

Library2 defines a Library2Exception that inherit from CommonException (defined in CommonLibrary).
When I call, in the first AppDomain, a method on a MarshallByRef of the second AppDomain that throws a Library2Exception, a SerializationException is thrown.

Indeed, .Net tries to deserialize Library2Exception but this type is defined in Library2 which is not found in the first AppDomain. I want it to become a CommonException that I can handle.

So, my questions are :

• How can we control serialization between AppDomain like a SerializationBinder would do on a BinaryFormatter?
• Is it possible to have an exception ByRef instead of ByValue (serialized) ?

Answer 1

I found! Override GetObjectData to change the exception type :

  [Serializable]
  public class CommonException : Exception
  {
    public CommonException() { }
    public CommonException(string message)
     : base(message) { }
    public CommonException(string message, Exception inner)
     : base(message, inner) { }
    protected CommonException(
    SerializationInfo info,
    StreamingContext context)
      : base(info, context)
    { }

    public override void GetObjectData(
    SerializationInfo info,
    StreamingContext context)
    {
      if (context.State == StreamingContextStates.CrossAppDomain)
        info.SetType(typeof(CommonException));
      base.GetObjectData(info, context);
    }
  }