Lack of sent field from subclass in WCF - trying to gain polymorphism

Question

First of all keep in mind, that I followed a very much stuff in google about this subject.
I am using WCF, to exposing some services. I have something like:

Answer 1

As I understand, you want to manually send correct XML to your service and make it recognize the Sub entity. In my comments to your question I mentioned approach with KnownTypes discovery, but it is solving another kind of problems.

Your current C# code looks ok, but you are missing some type attributes in the XML. It should look like this:

   
   
      
         
            1
            2
         
      
   

I just tested it and it worked fine in a WCF project created with VS 2015 and tested with SoapUI. Both sub and base values reached the test method and Sub entity was available inside of it.

A similar question on StackOverflow with the same xsi:type solution also given here.

If this does not help enough, I can upload the demo project somewhere on GitHub.