At Microsoft PDC 2009 I gave a talk entitled “Developing Testable Silverlight Applications”. We looked at how to use the Inversion of Control principle with the Model-View-ViewModel design pattern to isolate the dependencies within a Silverlight 4 application for easier testing. We also saw how to improve testability by taking advantage of the natural boundaries in Silverlight applications utilizing WCF RIA Services to query for data and persist units of work. There was so much material to cover during my session that I am going use a series of blog posts to provide more in-depth detail on the techniques I talked about....

A customer recently asked how to change the selection of a row in the Silverlight 3 DataGrid based on the values of the columns. The brief answer is to add an event handler for LoadingRow and call dataGrid.SelectedItems.Add(e.Row.DataContext), but the...

Due to the async nature of the .NET RIA Services programming model, exceptions and errors during load and submits aren't thrown on the client. Instead, the errors are exposed through an Error property which can be found in the event args instances passed...

The Slider control that shipped with the Silverlight 2 Beta 1 SDK only supports picking a single value. Back at Mix08 in March I threw together a control that allows selecting a range using two thumbs, but I haven't had a chance to talk about it until now. So, without further ado let me introduce the RangeFinder control....

Hosted by Silverlight Streaming Ta-da! Here's a new look for the WatermarkedTextBox (a.k.a. WTB) in Silverlight 2 Beta 1. This was relatively simple to do just by changing the template. Here is the XAML for the template: < ControlTemplate...

For hard-core XAML programmers or just to boost performance when working with XAML files in VS 2008, you may want to have the default view be just the XAML editor (no designer visible). To do so, select the Tools->Options... menu item. Then navigate...

Remember, it is a beta so there are going to be some things that are by design and others which just need temporary workarounds. Here are some things I learned when developing and testing some of the controls delivered as part of the Silverlight 2 Beta...