How to implement Workflow 4.0 Services ReceiveAndSendReply activity without the Designer

I wa开发者_JAVA技巧nt to write a code activity as a workflow service, using the Receive or ReceiveAndSendReply activities, but I do not want to use the Designer. What's the best way to define the WCF endpoint and service/data contracts (the Designer would normally determine them and build them into a xamlx file, but I want to do all this in code).

The Receive and SendReply are just classes you can new. Take a look at this blog post where I create WF4 service using just code.

BTW the ReceiveAndSendReplyis not an activity but a template that preconfigures a Receive and SendReply inside of a Sequence for you when you drag it onto the design surface.