I cannot count how many times people have requested the source code to the ATAPI.NET or ITAPI3 projects. My response has always been that I was unable to release it due to ownership issues (it was developed under contract for a client). am pleased to announce this morning that I have worked through those issues and have been granted permission to release the project in it’s entirety as source code on CodePlex! Here’s their new homes: [link] and [link]. ll open up discussion board access there as well for Q&A.

I’ve published it to [link] where I’ll continue to maintain and add to it. Get the latest release from there

In the last post, I referred to the DragPositionBehavior in the JulMar MVVM library. This behavior allows any UIElement to be dragged and repositioned using the mouse without requiring any code logic on your part. It’s easy to apply – using the traditional Blend syntax (easiest done by dragging the behavior onto an element): {rtf1ansiansicpglang1024noproof65001uc1 deff0{fonttbl{f0fnilfcharset0fprq1 Consolas;}}{colortbl;??red163green21blue21;red255green255blue255;red0green0blue255;}??fs28 red163green21blue21;red255green255blue255;red0green0blue255;}??fs28 fs28 cf1 cf3 par ??cf1 cf1 cf3 par ??cf1

In this post, we will look at the IUIVisualizer , and bring together some of the concepts we’ve talked about already through a new sample – a simple picture viewer: The application grabs all the images from the user’s photo folder and then displays each one onto the surface of a corkboard. You can change the properties of an image, remove an image or add additional images. It’s not designed to be a true image application ala photoSuru, it’s really more of a sample of MVVM practices with the helper library. It displays a “Picture Properties” dialog using the IUIVisualizer service. par ?? par ??

In this post, I will go over the simple message visualizers available in the MVVM Helpers toolkit. Essentially the idea is that it is fairly common to want to display a simple message from the ViewModel to the user. Since the VM is supposed to be testable, we encapsulate this ability into four services, three of which I’ll focus on here: IMessageVisualizer. Displays a title + message to the user and allows them to dismiss it through a set of user-defined buttons. The button used to dismiss the dialog is returned as the result. IErrorVisualizer. INotificationVisualizer. IUIVisualizer. par ??

A question I got recently was how to manage Radio Buttons with bindings – in this instance, the sample code was trying to map a single value to a set of Radio Buttons based on an enumeration set. The original implementation was using a Value Converter to compare the “bound” value with the enumeration value expected for that radio button choice – if it was equal then the converter returned true, otherwise false. Something like this: {rtf1ansiansicpglang1024noproof65001uc1 deff0{fonttbl{f0fnilfcharset0fprq1 Consolas;}}{colortbl;??red163green21blue21;red255green255blue255;red0green0blue255;red255green0blue0;red0green0blue0;}??fs28

The main project I’ve been working on the past few months has been a rRNA sequencing application. It’s a joint project involving Microsoft Research and the University of Texas in Austin. The goal being to produce lightning fast visualizations (nucleotide, 2D and 3D) with very large (100,000 sequence) data sets on WPF. It’s been a big learning experience for me in many ways because the traditional mechanisms for dealing with things in WPF just flat out fail when we load big datasets and start scrolling them around. rCAT 4.0 And it, of course, is all MVVM. Fun stuff

The View – Model – ViewModel design pattern, also known as MVVM, is getting more popular these days. have found it extremely easy to use when developing very different applications and have used the design pattern recently in both ASP.NET, WPF and Silverlight applications. However easy as it might be is seems to confuse people as I have seen some terrible examples where people make a complete mess of things. Josh Smith did an excellent screen cast for Pixel8 on using MVVM with WPF, you can find it here. The View is data bound to a ViewModel. This is the most important step to remember. 11: {.

Note: This blog post is written using the.NET framework 4.0 Beta 2 With Windows Workflow Foundation 3 it was possible to rehost the workflow designer in your own application. But possible is about all there was to say about it as it was pretty hard to do anything beyond the basics. With Windows Workflow Foundation 4 live has become much better on the rehosting front In fact it is possible to create the fully functional and useful workflow editor below in about 200 lines of code. Now that is more like it! The WorkflowDesigner The WorkflowDesigner is the main class to work with. null ). {. Sweet.

Using the declarative DomainDataSource that is part of the upcoming Silverlight 3 RIA services makes it quite easy to work with data. All you need to do is add a DomainDataSource control to the the XAML, point it to the generated DomainContext class (in this case NorthwindContext) and tell it which method to use to load the data from the web service(in this case LoadCustomers). Next add a DataGrid to display the data and you are good to go. Adding paging. Sometimes the lost of data to load can get somewhat large and you might not want to load all data. Using progressive loading. Enjoy!

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. In fact Windows Workflow Foundation 3 was the first version and 3.5 added only very few features and some bug fixes. And as WF 4 is a complete rewrite we should approach it as a new product and forget just about everything we already know about WF 3. That might be a bit surprising, after all we still have activities and a workflow runtime right?

There are quite a a few cases where it is useful to have a duplex communications. An obvious candidate is allowing a service to notify the user interface application of the progress so the user knows what is happening. Normally, when using plain WCF , you would use a ServiceContract attribute with a CallbackContract that specified the service uses duplex communications. For example something like the following code on the server: [ServiceContract(CallbackContract = typeof (IService1Callback))]. public interface IService1. {. OperationContract]. string GetData( int value ); }. ServiceContract].