MSDN Magazine - December 2008 - (Page 52)

Real-WoRld WF Best Practices For Windows Workflow Foundation Apps Josh lane Since its release as part of the Microsoft .NET Framework 3.0, I’ve spent a lot of time with Windows Workflow Foundation (WF), implementing systems with the technology and teaching others to do the same. These experiences have given me some insights into some best (and less-than-best) practices to consider when using WF to realize software solutions in the real world. My experience has been that WF suffers from something of an identity crisis. Many developers I talk to understand, at some level, what’s going on in WF: conditional logic, flow control, atomic actions, and so on. “Yes, I think I understand. You drag shapes onto the design surThis article discusses: • The workflow programming model • Workflows and services • Unit testing workflows • Plugging WF into your solution Technologies discussed: Microsoft .NET Framework 3.5, Windows Workflow Foundation, Visual Studio 2008 Code download: code.msdn.microsoft.com/mag200812WF 52 msdn magazine face. These represent actions that execute in some sort of ‘flowchart’ sequence. Yes, that certainly is clever!” This can be followed by mild protests along the lines of “But what would I use this for?” or “But I can do this already in C# or Visual Basic!” In the abstract, these are not unreasonable objections. But while it’s true that the public face of WF is the drag-and-drop designer experience in Visual Studio, and that a superficial look at the features of WF will uncover capabilities seemingly found elsewhere, the real benefits of WF are found underneath the surface. To appreciate the value of WF, it’s useful to consider some historical context. Since its inception, a primary goal of the .NET Framework has been to raise the level of abstraction at which Windows software programs are constructed. COM, HRESULTs, smart pointers, MTAs, message pumps, thunking layers … the sheer number of non-domain-specific details a Windows programmer needed to grasp could be overwhelming. Thankfully, the .NET Framework has succeeded in turning most of these details into historical trivia. Indeed, most of us developers take for granted that we can open up Visual Studio and immediately start writing code that maps directly to the problem at hand. We’re happy to let the .NET runtime worry about issues such as memory management, enforcement of security policy, runtime resolution of code dependencies, and countless other details. As a result, many developers are far more productive today than they’ve ever been before. http://code.msdn.microsoft.com/mag200812WF

Table of Contents Feed for the Digital Edition of MSDN Magazine - December 2008

MSDN Magazine - December 2008 Contents Toolbox CLR Inside Out Advanced Basics Cutting Edge Patterns In Practice Team System Real-World WF Visual Studio OBA Tools SOA Data Access Geneva Framework Test Run Foundations Windows With C++ Going Places End Bracket

MSDN Magazine - December 2008

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