March, 2011

I don’t remember anyone ever actually asking me this, but I found myself wondering the question while rustling up a quick rehosting app. Foreach<> activity lets you change the TypeArgument dynamically via the property grid. But FlowSwitch<> doesn’t. Why? As usual, although it take a while, I like investigating issues like this in a practical way. Is it possible for us to ‘Add’ the TypeArgument property in the property grid for FlowSwitch<> in the same way that ForEach<> does...

Last year we at PDC10 we gave you a preview of the next release of Windows Workflow Foundation.  The video has just been posted to Channel 9. Windows Workflow Futures Speaker: Ron Jacobs Learn about the key investments we’re making in Windows Workflow Foundation (WF). See the WF improvements we’re working on for workflow authoring, hosting and management. Learn how we’re bringing WF to the cloud, and how WF and Windows Azure AppFabric will provide a great middle-tier platform for building, deploying...

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 . Going down the list of behaviors, the second one to be covered is the IContractBehavior . Like the other ones, it can be used to inspect or change the contract description and its runtime for all endpoints which have that contract. For example, the behavior can validate the contract against the binding to ensure that the it’s used the contract is only used...

A long time go in a galaxy very, very close (so close it could be coincidental or indeed the same) I remember writing a couple things which touched upon Undo and Redo in workflow designer. Since someone invented hyperlinks, I should probably use this neat feature of the interwebs and point you at them. “Undoable Layout for the Freeform Canvas Activity Designer” - This article contains exploration around the idea of building a Custom Flowchart Designer. In the article I found that it is hard to get...

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 first behavior covered in this series is the IServiceBehavior . It can be used to inspect or change the entire service description and runtime. For example, to collect information about all endpoints in the service, to apply some common behavior to all endpoints in the service, anything which affects the global service state, the service behavior is a...

I don’t remember anyone ever actually asking me this, but I found myself wondering the question today while rustling up a quick rehosting app. Foreach<> activity lets you change the TypeArgument dynamically via the property grid. But FlowSwitch<> doesn’t. Why? As usual, although it take a while, I like investigating issues like this in a practical way. Is it possible for us to ‘Add’ the TypeArgument property in the property grid for FlowSwitch<> in the same way that ForEach<>...

Windows Communication Foundation (WCF) is Microsoft’s unified programming model for building service-oriented applications. Windows Server AppFabric provides tools for managing and monitoring your web services and workflows. WCF HTTP Service is a service that can be accessed by a simple HTTP POST/GET request and can return responses in plain XML and in JSON formats. The AppFabric WCF HTTP Service template brings these two products together providing the following features: Monitor the calls to your...

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 first part of this series will focus on the behaviors. There are four kinds of behaviors, depending on the scope to which they apply: service, endpoint, contract and operation behaviors. The behavior interfaces are the main entry points for almost all the other extensibility points in WCF – it’s via the Apply[Client/Dispatch]Behavior method in the behavior...

How should you use WF4 and WCF with ASP.NET?  For this post I’ve created a really simple workflow and WCF service that delay for a specific amount of time and then return a value.  Then I created an ASP.NET page that I can use to invoke the workflow and WCF service to test their behavior The Workflow Definition First off – let’s get one thing straight.  When you create a workflow, you are creating a workflow definition .  The workflow definition still has to be validated, expressions...

Last week the data team shipped the Release Candidate of Entity Framework 4.1.  You can learn more about it and download it here . EF 4.1 includes the new “EF Code First” option that I’ve blogged about several times in the past.  EF Code First provides a really elegant and clean way to work with data, and enables you to do so without requiring a designer or XML mapping file.  Below are links to some tutorials I’ve written in the past about it: Code First Development with Entity Framework...

Under development you may create a self-signed cert to use when you deploy a web role to Azure. If this certificate is not properly created, when you deploy the web role, it will recycle constantly and you will be unable...

Even when AsyncCodeActivity.Cancel is called, the activity will still execute the EndExecute method, so it isn't immediately obvious why a second path of execution is necessary. Implementing this method is useful only when AsyncCodeActivityContext.MarkCanceled is implemented, which in turn is useful mainly when cancellation is meaningful for the underlying operation (i.e. if work already completed can be rolled back). In order to implement cancellation in a useful way, do the following: Call...

The other day, I walked by the office where our team members from Shanghai work while in Redmond and I ran into Leo Shum, a test lead on the new WCF Web HTTP (REST) Test Tool. On this episode, Leo joins me in the studio to show you how this new tool works. Though it's not yet shipping, we definitely want to know what you think and how we can make it better. So take a look and let us know! Ron Jacobs http://blogs.msdn.com/rjacobs Twitter: @ronljacobs Blog Post by: Ron Jacobs

Last week we shipped Service Pack 1 of Visual Studio 2010 and the Visual Studio Express Tools.  In addition to bug fixes and performance improvements, SP1 includes a number of feature enhancements.  This includes improved local help support , IntelliTrace support for 64-bit applications and SharePoint, built-in Silverlight 4 Tooling support in the box, unit testing support when targeting .NET 3.5, a new performance wizard for Silverlight, IIS Express and SQL CE Tooling support for web projects...

Now available Download the AppFabric WCF Service Template C# Windows Communication Foundation (WCF) is Microsoft’s unified programming model for building service-oriented applications. Windows Server AppFabric provides tools for managing and monitoring your web services and workflows. The AppFabric WCF Service template brings these two products together providing the following features: Monitor the calls to your service across multiple servers with AppFabric Monitoring Create custom Event Tracing...

To access environment information from within an activity, you'll need to use the System.Activities.Hosting.SymbolResolver class. Here's the code to access the symbol resolver from within an activity: public sealed class SymbolUser : CodeActivity { protected override void Execute(CodeActivityContext context) { SymbolResolver symbolResolver = context.GetExtension<SymbolResolver>(); MyObject obj = symbolResolver["CustomObject"] as MyObject; Console.WriteLine(obj.MyString); ...

(Category: Rambling) Sometimes it’s funny how the same simple problem comes up over and over again, and people immediately solve it over and over again. Of course usually I only notice it when I am one of those people. Some time back I found myself writing a INotifyCollectionChanged collection synchronizer for working around a ModelItemCollection bug in workflow designer. The bug we were working around was nothing to do with change notification at all. The workaround was basically to create a ValueConverter...

A few weeks ago I blogged about a great ASP.NET MVC 3 video training course from Pluralsight that was made available for free for 48 hours for people to watch.  The feedback from the people that had a chance to watch it was really fantastic.  We also received feedback from people who really wanted to watch it – but unfortunately weren’t able to within the 48 hour window. The good news is that we’ve worked with Pluralsight to make the course available for free again until March 18th. ...

The excellent DevConnections conference will be held in Florida later this month (March 27th to 30th).  DevConnections features multiple concurrent tracks – including ASP.NET Connections, Silverlight Connections, Visual Studio Connections, SQL Server Connections, and SharePoint Connections. I’ll be doing a keynote on the first day, and there will be dozens of fantastic talks that week by some of the best presenters in the .NET community.  You can learn more about the conference here . I...

The following error might occur when an activity executes: The argument of type '<type>' cannot be used. Make sure that it is declared on an activity. If the type above refers to an implementation child, then it's possible that it's being created in the Execute method of the activity. If this is the case, try moving it to the CacheMetadata method- this is the method that tells the runtime about the implementation details of the activity. Adding an implementation child during...