I've got a RadGridView in a WPF 4.5 app I'm working on, which involves grouping. I had a hard time trying to get the data to work initially in the designer (it's coming from a WCF service), but want to be able to do styling of the GridView with sample data. I found an article on MSDN called Walkthrough: Using Sample Data in the WPF Designer, which is helpful, but not entirely complete for the RadGridView. For example, that article discussed opening the ItemsSource property of the out-of-the-box DataGrid control. I tried doing that with the RadGridView, but it didn't work. I'm guessing I'm doing something wrong, but am not sure what, so I would like some direction, please.