One thing that many web sites do is to verify email addresses by sending you an email to complete registration.  I decided to build a Registration system for ASP.NET MVC using Windows Workflow Foundation. When you create a new ASP.NET MVC web site, the site comes with a simple account controller...

In my previous posts I’ve been arguing that you can implement Task Parallelism with Windows Workflow Foundation (WF4).  This post is a part of a series on WF, Parallelism and Threading Windows Workflow Foundation (WF4) Activities and Threads The Workflow Parallel Activity and Task Parallelism Windows...

In my last post The Workflow Parallel Activity and Task Parallelism I said that you can implement Task Parallelism with Windows Workflow Foundation.  In this post I want to explore some of the differences between the Parallel Activity in System.Workflow.Activities (WF3) and the Parallel Activity...

“ Task parallelism (also known as function parallelism and control parallelism ) is a form of parallelization of computer code across multiple processors in parallel computing environments. Task parallelism focuses on distributing execution processes (threads) across different parallel computing nodes...

Most of the time in software when we say “Parallel” we mean that multiple threads are being used to do work concurrently.  Because of this, many customers ask if the Parallel activity works this way in Windows Workflow Foundation.  I know there is a great deal of confusion about activities...

With Windows Workflow Foundation (WF4) you can author activities in Code or XAML.  Each has advantages and disadvantages Visibility Advantage – XAML You can author them in the Workflow Designer.  Here is a activity I’ve been working with today.  You can easily see what this activity does...

Recently I was contacted by a customer who had read my posts on Versioning and was investigating some interesting behavior of activity designers (more on this in a future post).  But this discussion got me to thinking.  As I pointed out in my WF4 Activity Versioning Solution , with compiled...

For background on this issue see WF4 How To Invoke a Child Workflow as XAML .  Thanks to rfcdejong who recently logged an issue on our http://wf.CodePlex.com site Child activity's ignore the Tracking Participant / Tracking Profile ? Because of this feedback I’m adding support for tracking to InvokeWorkflow...

In my previous post on WorkflowServices, CanCreateInstance and Silverlight I shared with you some of the pain that I went through in building my first Silverlight / Workflow Services app. Much of this pain was just because I have not done a great deal of work with Silverlight and WCF. In this post I’m...

While working on signing assemblies you may run into a problem I encountered this morning so here goes… Problem XamlBuildTask fails when referencing a Delay Signed assembly To see this in action try the following Create a Workflow Console Application (WorkflowConsoleApp1) Create an Activity Library ...

If you are using .NET 4 Platform Update 1 to do unit testing you may encounter this dialog box when you try to change the target framework of your test project Tip: You can press Ctrl+C on a message box to copy the text to the clipboard.  If you want to go to the link mentioned in the message box...

tempuri.org is the default namespace applied to WCF Services and Workflow Services.  You can and should specify your service namespace. It is recommended that you explicitly specify a name and namespace for the service contract, and an action for each operation to avoid using " http://tempuri...

So you want to know how the state machine really works? Take a look at the WF4 State Machine Explorer .  This sample is designed to show you how StateMachine works with activities. There are three transitions from State1. To State 2 which is triggered by a bookmark named “State2” To State 3 which...

Humans Go to Control Panel / Programs / Programs and Features / View Installed Updates Use the Search Box to search the updates for KB2495593 KB2478063 Or if you prefer, search the list your self Microsoft .NET Framework 4 Platform Update 1 - Runtime Update Look for .NET Framework 4 Extended Look for...

Today I’m starting on another spike project.  So far there are only questions to investigate, no answers.  I’m sharing my plans with you because I believe doing so might help some of you and I’m hopeful that you might share your insights with me as we seek to solve this problem together. But...

If you are a C# developer using Workflow you might not know how VB does type conversion. Imagine this simple example.  I’ve got some classes which use inheritance 1: public abstract class Shape 2: { 3: public int Top { get; set; } 4:   5: public int Left { get;...

Recently somebody asked me how a workflow could invoke another workflow that is loaded as XAML from a file or a database. This is a common request so I’ve added an activity to Microsoft.Activities to support this. Update: If you want tracking to include data from the child workflow be sure to...

How should you use WF4 and WCF with ASP.NET? Download Sample Code - Windows Workflow Foundation (WF4) - How to use Workflow from ASP.NET endpoint.tv - ASP.NET WF4 / WCF and Async Calls For this post I’ve created a really simple workflow and WCF service that delay for a specific amount...

Thanks to Jean-Sebastien who contacted me with this question. Imagine you have the following service contract 1: public interface IBaseMyServiceContract 2: { 3: [OperationContract] 4: string CallAMethod( string correlationHandle, string data); 5: } Now suppose you want...

“The important point is that our test can’t control what that dependency returns to our code under test or how it behaves (if we wanted to simulate an exception, for example). That’s when we use stubs .” – The Art of Unit Testing - Roy Osherove, Yesterday morning I...

With the work I’ve been doing on versioning I’ve had to write unit tests that verify the behavior I expect from the helper classes in Microsoft.Activities.dll .  If you want to verify that your assembly versioning strategy is working correctly you may have to do similar testing.  This sort...

In my last post I showed you how the _XamlStaticHelper class uses different semantics when loading assemblies referenced by XAML files. Today I’m going to show you a solution I’ve built into the Microsoft.Activities library that can help you apply standard CLR behavior when loading referenced assemblies...

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...

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...

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...