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Windows Workflow Foundation 4 and persistence
The whole persistence model has changed quite a but for WF4.   The persistence class out of the box is called SqlWorkflowInstanceStore and as the name suggests it saves workflow data in either SQL Server 2005 or 2008. It is based on the InstanceStore...

Posted by Maurice | 1 comment(s)

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Flowcharts in Workflow 4 and the Switch activity
Flowcharts are a nice addition to Windows Workflow Foundation 4. They allow for a lot of pretty complex behavior that is hard to do in a sequential workflow. In WF 3 we used to model these complex behaviors as state machine workflows. That worked but...

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Workflow 4 and Visual Basic expressions
When using Windows Workflow Foundation 4 you often need to enter expression in some activity property. The new thing is these expressions are all in the Visual Basic dialect regardless of what language you project is in. So when developing a project in...

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Workflow parameters in Window Workflow Foundation 4
Creating parameters for a workflow is quite easy to do in WF 4. Just open the arguments tab in the workflow and add each input or output parameter you need and the required type.   Now in WF 3 passing data to a workflow was done using a Dictionary<string...

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Nederlandse CodeCamp 2009
Op 21 november 2009 organiseren de SDN , Stichting dotNed en VBcentral samen het derde Nederlandse Code Camp . Dit is een dag lang met code, code sharing, freaking en gezellig samenzijn. Een evenement door ontwikkelaars, voor ontwikkelaars. De regie ligt...

Posted by Maurice | 1 comment(s)

WF4&WCF and message correlation
In the previous blog posts, here , here and here , I demonstrated how to  use WCF from WF4. This same some more about sending multiple messages to the same workflow, AKA Workflow Correlation.   One of the ugly parts of Windows Workflow Foundation...

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Sending your own objects to a WF4 workflow
In the previous two blog posts ( here and here ) I showed how to create and expose a Windows Workflow Foundation 4 workflow via WCF and have both a workflow and a regular C# client work with it. But the parameter and return value where real simple with...

Posted by Maurice | 5 comment(s)

Using Windows Workflow Foundation 4 Receive from an non WF client
In a previous blog post I described how to use the WorkflowServiceHost and host a workflow with a Receive activity that waits for WCF messages. I also added a WF4 client that called the service and received a response. However a lot of clients out there...

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Combined DevelopMentor instructors blog feed.
Michael Kennedy , one of the co instructors from DevelopMentor , has created a combined feed from all the blogs of the various DevelopMentor. An awesome group of people with a lot of knowledge to share. Highly recommended in you RSS reader. http://feeds...

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Combining WCF and WF4
There are several ways to use WCF in combination with Windows Workflow Foundation 4. The two can be combined inside of a XAMLX file as Ron Jacobs describes here . Another option is using the WF4 Receive and SendReply activities and hosting the workflow...

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Data and Windows Workflow Foundation 4
  One thing that has completely changed in Windows Workflow Foundation is the way we work with data in a workflow. In WF 3 we used properties to store data. We could use regular .NET properties but most of the time dependency properties where the...

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More asynchronous work in Windows Workflow Foundation 4
In my previous post I showed how to use an AsyncOperationBlock to do some basic asynchronous work in WF 4. As I mentioned this was for relatively short lived asynchronous operations as the workflow could not be persisted and unloaded while this asynchronous...

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Basic asynchronous work in Windows Workflow Foundation 4
The whole asynchronous execution model in WF 4 has changed quite a bit from WF 3. Not really a surprise as this one of the areas where WF 3 was really hard to work with.   Below is a very simple example. It does nothing useful, it’s only task is...

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What does Windows Workflow Foundation 4 mean for existing workflow developers?
  The question of what Windows Workflow Foundation version 4 means for developers currently developing using WF recently came up. As I mentioned before WF 4 is a complete rewrite and doesn’t use any of the existing WF 3 classes. The design of WF...

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Passing data into a Windows Workflow Foundation 4 workflow
Passing parameters into a workflow is similar in WF4 as it was in WF3. In both case a Dictionary<string, object> is passed in when creating the workflow instance object. Alternatively when using the WF4 WorkflowInvoker you can pass it into the Invoke...

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The new Windows Workflow Foundation 4 runtime
With WF3 there was a central workflow runtime environment called the WorkflowRuntime and used to manage the lifetime of workflow instances. In WF4 this central class no longer exists and we manage individual workflows. To compare the two, this is what...

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Getting started with Windows Workflow Foundation 4
As you may have heard Windows Workflow Foundation 4 is not an upgrade from Windows Workflow Foundation 3 (or 3.5). The version numbers might suggest that the previous version was quite mature but in fact it refers to the version of the .NET framework...

Posted by Maurice | 5 comment(s)

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Using Windows Workflow Foundation with Windows Communication Foundation
Attached are the PowerPoint presentation and samples from my WF with WCF presentation in Timisoara, Romania. Thanks to Ineta for providing the funding for this. Download the PowerPoint and samples

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Unleash the power of State Machine Worklfows
Attached are the PowerPoint presentation and samples from my state machine workflow presentation in Timisoara, Romania. Thanks to Ineta for providing the funding for this. Download the PowerPoint and samples

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Using a TransactionScopeActivity with a WCF ReceiveActivity revisited
Last year Marcel and I worked on a problem using a TransactionScopeActivity inside a WCF ReceiveActivity. I blogged a number of time about our finding, for example here . Last week I heard from Marcel that a hotfix was finally available that solves this...

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