April, 2011

This post is part of a series about WCF extensibility points. For a list of all previous posts and planned future ones, go to the index page . The next behavior in the list is the IEndpointBehavior . Like the other ones, it can be used to inspect and change the endpoint description (which includes the contract description) and its runtime. Unlike the other behaviors, Endpoint behaviors cannot be applied to endpoints as attributes (unless the attribute is applied to an implementation of a callback...

I got lost in some circle of WPF hell this afternoon. Eventually I started wondering if using ICollectionViewFactory to instantiate a collection view would be the cure to all my problems. However, I found myself banging my head against brick walls just figuring out how to use ICollectionViewFactory. In the process I noticed (again) that MSDN docs for interfaces are sometimes really quite useless. For instance, that an interface designed as an extensibility hook actually will , in some scenario, be...

Here’s a workflow designer FAQ finally getting the attention it deserves, and helping show off how to do custom property editing in designer. “How do I show an InArgument<bool>/<enum> in the property grid as a checkbox/combobox?”   [Aside: Before we start the guide, note that actually doing the thing you are asking about has certain implications, and that there’s one obvious alternative that works in some cases: using a plain property, instead of an InArgument<T> typed-property...

When loading an activity assembly using Assembly.LoadFrom, you may see the following error: "Error: The values provided for the root activity's arguments did not satisfy the root activity's requirements: 'UserDefinedInputClass': Expected an input parameter value of type 'MyAssembly.UserDefinedClass' for parameter named 'UDC'. Parameter name: rootArgumentValues" Assembly.LoadFrom does not use the main application context; instead, a new context is used, so...

Link - “TFS and WF4- The diff noise problem” - I just saw this post from Rory which looked useful for anyone using WinMerge (it’s free). Of course not everyone uses the same diff tools. I’m rather partial to  SourceGear|DiffMerge (also free), which is configurable in much the same way. Here’s DiffMerge’s way of setting up the same XAML/XAMLX rules (otherwise similar to the XML rules) Inside the rule, un-tick ‘Classify Differences as Important’. Blog Post by: tilovell09

Today we’re going to explore some internal aspects of ModelItem and its subclass ModelItemImpl. For your reference, ModelItemImpl is an internal class, making what we talk about below ‘implementation detail’, according to a narrow view based on which APIs are actually visible by way of being marked ‘public’, and therefore more likely to change in future framework versions (than something actually marked public and therefore having a 1 line API doc somewhere). Now stop worrying about such minor details...

This post is part of a series about WCF extensibility points. For a list of all previous posts and planned future ones, go to the index page . The last of the behavior interfaces in WCF is the IOperationBehavior . The scope of this one is limited to an individual operation, so one can have different operations in the same contract. For example, the OperationBehaviorAttribute can define that some specific operations in the contract will auto-complete transactions (if the operation returns successfully...

In my investigation of versioning issues with Windows Workflow Foundation I’ve come to one important conclusion.  This isn’t something new, in fact at TechEd 2008 when I gave my very first “chalk talk” about WF3.5 I said that this issue (versioning) was going to be something that you must plan for. As architects and developers, we are often so focused on getting to Version 1 we rarely think about what will happen when we need to move to Version 2.  Of course, we know version 2 is going...

On March 25 th at his Tech-Ed India keynote Jason Zander announced some great new resources for developers. Our team has been working hard on these releases and I’m happy to share with you that on April 25 th the Multi-Targeting Pack for Microsoft .NET Framework 4 Platform Update 1 (KB2495638) will be available for download. Windows Workflow Foundation - State Machine (.NET Framework Platform Update 1) New State Machine workflow model - builds upon WF runtime and add in new workflow style for...

This Friday, April 22nd, I’ll be holding my 8th Annual “Day of .NET” event in Arizona.  Organized by my friend Scott Cate, this all-day event is free and contains a ton of great content and presentations on recent technologies in the .NET world.  It is hosted in a great facility and is a lot of fun. This year I’ll be presenting together with Mark Russinovich, and we’ll be covering ASP.NET + Azure + Silverlight + Windows Phone 7.  It will be great! You can learn more about the event...

The Microsoft .NET Framework 4 Platform Update 1 released today, 4/18/2011. The Microsoft .NET Framework 4 Platform Update 1 is a platform update that is a set of new features that provides additional functionality for top customer requests and important scenarios. The features that are enabled in this update are: Windows Workflow Foundation (WF) State machine workflows New classes added: StateMachine , State , FinalState , Transition , StateMachineStateQuery , StateMachineStateRecord SqlWorkflowInstanceStore...

Most of the Windows Workflow Foundation samples use workflows that are hosted in a console application, but this isn't a realistic scenario for real-world workflows. Workflows in actual business applications will be hosted in persistent processes- either a Windows service authored by the developer, or a server application such as IIS or AppFabric. The differences between these approaches are as follows. Hosting workflows in IIS with Windows AppFabric Using IIS with AppFabric is the preferred...

This post is part of a series about WCF extensibility points. For a list of all previous posts and planned future ones, go to the index page . Before starting on the actual extensibility points for the WCF runtime (first post should be online tomorrow), I decided to write this quick introduction to the runtime itself. Unlike the behaviors, which are invoked when the WCF stack is being created, the runtime extensions are invoked when actual messages are being sent / received by WCF. As could be seen...

State machine is a well-known model for event-driven workflows and a highly requested feature from our WF4 users, especially those looking to move their WF3 State Machine workflows to WF4. We are very pleased to provide a new, fully-supported, WF4 State Machine including runtime and designer in the .Net Framework Platform Update 1 release ( KB2495638 ). This release enables customers to model their event-driven processes as a state machine using a simplified API and designer experience. Thanks to...

Hey everybody, just in case you haven’t heard the good news yet, our group released .Net Framework 4 Platform Update 1 today.  Hurray!   By the way, like me you may be confused upon hearing the term ‘platform update’ used this way. What does a .net framework platform update mean today? Good question. Normally you receive .Net framework updates in only a few ways, including releases (especially major version number changes, like ‘3.0’), and ‘fixes’, ‘patches’, and ‘QFEs’. The new releases...

This post is part of a series about WCF extensibility points. For a list of all previous posts and planned future ones, go to the index page . The message inspectors are probably the most used extensibility points of the WCF runtime. Anytime you need to log, inspect, modify or completely replace a message, the two inspector interfaces ( IClientMessageInspector for the client side; IDispatchMessageInspector for the server side) are likely to be perfect candidates for the solution. There are so many...

MIX was indeed a busy time for the WCF Team. We delivered several talks, and released several shiny new toys to the community for folks that are building web-based systems. WebSockets Craig Kitterman of our Interoperability group, and Paul Batum , whom you might know of from his work on Fluent NHibernate gave a talk: Hot from the Labs: HTML5 WebSockets In the talk they spoke about new explorations we are doing into supporting WebSockets in the Microsoft Stack. WebSockets is basically sockets for...

The folks over at DonorsChoose.org are running an "open data" context in April that I thought you all might be interested in! DonorsChoose is an online charity that makes it easy for anyone to help students in need. The difference is that the Donor can target a project directly...you can choose where your $1 goes. So far, more than 165,000 teachers at 43,000 public schools have posted over 300,000 classroom projects supported by 409,000 citizen philanthropists who have made >900,000...

The workflow designer has a rich programming model that supports communication with the host. A rehosted workflow designer will automatically validate a workflow when it is changed; in order to programmatically call validation on demand on a rehosted designer, use the following method: designer.Context.Services.GetService<ValidationService>().ValidateWorkflow(); To handle resulting validation errors, publish an implementation of IValidationErrorService, which will expose the set of errors through...

Sometimes when using Windows Workflow Foundation (WF4) you need to create a custom WorkflowServiceHostFactory.  There are a couple of main reasons why you would want to do this. To configure the WorklfowServiceHost in some way like adding an extension To do some other type of initialization work when auto starting a service This morning I was working on the WF4 Batch Processing Example (now Workflow Services and Auto-Start sample) to update it with things I’ve learned in the past few months...