6.9. WCF/Messaging Improvements

A number of enhancements have been introduced in WF4 to improve integration with WCF and to ease messaging scenarios.

6.9.1. Correlation

Correlation functionality first appeared in WF3.5 and allows you to route incoming messages to specific workflow instances based on their content or protocol used. For example, if you have a very long-running workflow where replies take weeks or months to return, it is important that when a reply is received it is sent to the correct individual workflow.

ReceiveAndSendReply and SendAndReceiveReply are the new activities discussed in the following sections that provide correlated send and receive activities with a number of new methods of correlation such as XPath and scope.