Professional Visual Basic® 2008

Chapter 27. Windows Workflow Foundation

While Windows Communication Foundation and Windows Presentation Foundation enjoy much of the attention, the .NET Framework 3.0 also comes with another "Foundation": Windows Workflow Foundation (usually abbreviated WF). WF can be a powerful tool in developing applications, as it provides a standard means of adding workflow to an application. Workflow refers to the steps involved in an application. Most business applications contain one or more workflows, such as the approval steps in an expense-tracking application or the steps involved in paying for a cart full of items at an online store. Normally, a workflow is created in code and is inextricably bound to the application. WF enables developers to graphically build the workflow, keeping it logically separated from the code itself. It also enables the workflow to change as the needs of the business change. These workflows may be as complex as needed and may integrate human processes or Web services.

This chapter looks at how you can take advantage of WF in your applications: how you can add and edit workflows, how you can integrate workflows into an existing business process, and how the graphical tools used to build workflows with Visual Studio can help you communicate with business users and avoid errors caused by mistakes in the workflow.

Workflow in Applications

Just what is workflow? It's a very heavily used word, and many developers use it in multiple contexts. For our purposes, it is the ...