Activities are the basic building blocks for workflows. The base activity library in Windows Workflow contains general-purpose activities to use for all workflows. There are activities for control flow, transaction management, local communication, web services, and more. These activities appear on the Toolbox window of the workflow designer. Some of these activities, like the CodeActivity, are simple. The job of the CodeActivity is to execute a block of code. Other activities, like the PolicyActivity, are more complex. The PolicyActivity can evaluate prioritized rules with forward chaining. We can build powerful workflows using just the activities inside the base activity library.
We are about to embark on a tour of the base activity library. Many of the activities here deserve a more thorough coverage, but our goal for this tour is to understand the basic capabilities of each activity type, and come away with an idea of when we can use each one. We will...