WSE 3.0 - Byte array being encoded as Base64 and not “MTOM-ing” to binary

[Peadar McMahon]

I have followed lots of examples of how MTOM/XOP works in WSE 3.0 and have set up my project exactly as it seems is required. I have a Byte array field that is designated as DataType:-base64Binary. In this I put the Byte array of the attachment I want to add. When I run the application and check the request, the data is encoded inline as base64, i.e. without the XOP Include element and associated MIME part.

My understanding of MTOM within WSE 3.0 was that, when encoding it will take any field designated as base64Binary and encode it as binary and move it to a MIME part, replacing it with an XOP Include element. That is to say, it just worked. But I have set the service, in the Reference file, to inherit Microsoft.Web.Services3.WebServicesClientProtocol and have set the RequireMtom flag to true, and it is still not encoding correctly.

Have I missed something here? Is there any other steps that should be implemented for this to work?

EDIT: After looking through my code for the 100th time, I am wondering if it might be due to the fact that I have to serialise the payload before running the ProcessMessage method. Does this sound like it could be a problem? The reason we have serialised is because the method we have to use accepts a "Payload" parameter which has a content property, this content property is an XMLElement property and the only way we can get this is to serialise the required class. But does this stop the MTOM recognising the data type of the base64 field and therefore not converted to binary with the MIME parts and XOP? Just really clutching at straws now.

[Peadar McMahon]

Ok I finally figured it out and it was to do with the serialisation before invoking the method. I rewrote the class that was passed in to the method so it didn't require an XMLElement as a property, and therefore a pre-serialised class, and passed that in. This works correctly, after only 3 or 4 weeks of work...If anyone wants more clarification I can try to get it down here.