Book Image

Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#

By : Kenneth Scott Allen
Book Image

Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#

By: Kenneth Scott Allen

Overview of this book

Windows Workflow Foundation (WF) is a technology for defining, executing, and managing workflows. It is part of the .NET Framework 3.0 and will be available natively in the Windows Vista operating system. Windows Workflow Foundation might be the most significant piece of middleware to arrive on the Windows platform since COM+ and the Distributed Transaction Coordinator. The difference is, not every application needs a distributed transaction, but nearly every application does have a workflow encoded inside it. In this book, K Scott Allen, author of renowned .NET articles at www.odetocode.com, provides you with all the information needed to develop successful products with Windows Workflow. From the basics of how Windows Workflow can solve the difficult problems inherent in workflow solutions, through authoring workflows in code, learning about the base activity library in Windows Workflow and the different types of workflow provided, and on to building event-driven workflows using state machines, workflow communications, and finally rules and conditions in Windows Workflow, this book will give you the in-depth information you need. Throughout the book, an example "bug reporting" workflow system is developed, showcasing the technology and techniques used.
Table of Contents (14 chapters)
Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#
Credits
About the Author
About the Reviewer
Preface

Chapter 2. Authoring Workflows

The workflow designer hosted in Visual Studio 2005 makes workflow design a drag-and-drop operation. In this chapter, we will build a workflow with the designer, and then take a detailed look at what happens behind the scenes. Ultimately, the workflow definition we see in the designer becomes a type in a .NET assembly. Because Windows Workflow is flexible, there are several paths available for the workflow to journey from designer to compiled type.

One approach is to author our workflows using a purely declarative style (using only XAML). We can also author workflows using a purely imperative style (using only C# or Visual Basic code). Finally, we can use a combination of XAML and code.

When a workflow is executing, these different approaches won't have a noticeable impact. When we are building workflows, however, the authoring styles offer various strengths and weaknesses we can align with our needs. We will examine the pros and cons of the available approaches...