I couldn't leave this one alone. While I was making the last episode I said that there was possibly another strategy for detecting states and transitions and that was to use Tracking data. In this episode I'll show you a better way to implement our WPF UI using the Model View View-Model (MVVM) pattern that does not require the state machine to have actvitivities to notify the model of state changes. The source including some really cool unit tests that make use of Microsoft.Activities.UnitTesting...

Just posted a new release of Microsoft.Activities.UnitTesting This release incorporates the Task Parallel Library to greatly simplify test code. Episodes You can now create a task that will run an episode of work in the workflow. An episode is simply a pulse of work that the workflow runs. For example an episode might look like the following Thread Action host Run the workflow host Wait for idle Workflow Activity 1 Workflow Activity 2 (creates a bookmark) Workflow Invoke Idle delegate - host sets...

Andrew Zhu works for Microsoft in Shanghai and has been using WF4 since the very early days.  He frequently answers questions on our internal mailing list and on the WF Forums so when I heard that he was writing a book about WF4 I knew it would be a good one. I just got my electronic copy and I have to say it looks great.  Of course it covers the basics but also gets into great detail especially in the chapter on rehosting the WF designer, it’s definitely on my recommended list. Check it...

Auto-start is a really cool feature of Windows Server AppFabric. Recently I was asked about how you can do some kind of process initialization in your code with Auto-start (which the documentation implies that you can do). This led to a discussion with a number of questions that we want to address What does Auto-start really do? How much faster is the first call to my service if I use Auto-start? How can I write code that is called when the service is auto-started? endpoint.tv - WCF and AppFabric...

Recently I saw a message on the WF4 Forum where someone was asking for help learning how to consume a WCF service from a Workflow. In this post I’m going to walk through how you can consume a WCF service from a Workflow where both the service and the workflow live in the same web site. This should be simple, but unfortunately it is not as simple as it should be. Create an ASP.NET Web Application Start Visual Studio 2010 and Create a new ASP.NET Web Application Add a new WCF Service to the project...