Microsoft® Windows® Workflow Foundation Step by Step

Using the EventDriven Activity

EventDriven acts like a sequential activity in that it is a composite activity that executes its contained activities in a sequential manner. That’s not to say you can’t insert a Parallel activity in the container, but activities inserted prior to and after the Parallel activity will be executed in sequential order. The only rule for contained activities is that the very first activity in the execution path must be an activity that handles IEventActivity. (HandleExternalEvent and Delay are the two WF activities that qualify.) Aside from the properties and methods the Activity base class provides, EventDriven has no other methods or properties of use. (It’s simply a container.)

Unlike a sequential activity, however, ...