Professional Visual Studio 2012

Chapter 33

Windows Workflow Foundation (WF)

WHAT’S IN THIS CHAPTER?

• Understanding Windows Workflow Foundation
• Creating a basic workflow
• Hosting and executing a workflow
• Hosting the workflow designer in your application

Windows Workflow Foundation (WF) is a powerful platform for designing and running workflows — a central tenet in many business applications. WF was introduced with the .NET Framework 3.0 and was completely redesigned and rewritten for its .NET Framework 4.0 version to overcome some of the problems it had in its previous incarnations. This has the unfortunate side-effect of rendering .NET 4.0 workflows incompatible with workflows created in earlier versions, but leaving it a much more robust technology as a result. The version of WF included with .NET 4.5 includes a number of small, incremental changes in the designer and available templates, but nothing that rivals the difference between .NET 3.5 and 4.0. This chapter takes you through using the WF designer, and the process of creating and running workflows using WF.

WHAT IS WINDOWS WORKFLOW FOUNDATION?

Before discussing Windows Workflow, you should first examine exactly what workflow is. A workflow is essentially a model of the steps that form a business process. For example, this may incorporate document approvals, job status tracking, and so on.

A well-designed workflow requires a clear separation between the steps in the business process (the work to be done) and the business rules/logic that binds them (the ...