Question

In my WCF service I have implemented a custom encoder which inherits from System.ServiceModel.Channels.MessageEncoder.

In that encoder, I take the raw message and manipulate the received headers in my override of the ReadMessage() method.

During this manipulation, I may sometimes detect something in the header which makes the message invalid, and I want to return a useful exception to the client.

I have tried:

throw new Exception("Some useful message");

And:

throw new FaultException("Some useful message");

They both return an HTTP 400 to the client with no response body.

I can happily throw a FaultException from my actual web service method and this is returned to the client correctly, but at that late stage of the processing I no longer have access to the SOAP headers (unless someone can tell me otherwise).

How can I return a response 500 to the client with a friendly message based on information in the SOAP header?

Answer 1

You can call:

OperationContext.Current.IncomingMessageHeaders

in your service method to inspect the headers there if you wish. A custom MessageEncoder seems to me the wrong beast to be using to do what you describe.