There are a couple of ways to do this. You could simply use the built in Add Record functionality. With this functionality, the user starts typing into the Add Record area and when the user hits enter, the record is added. Check out the Feature Browser sample for how to use this feature.

If you want to do something different, you could add a PreviewKeyDown event handler to the Grid. In the event handler method you could check to see if the last record is selected. If it is, add a new record to your data source and the grid will update. After the new record is added you can select it using XamDataGrid APIs.

There are probably other ways to solve this since WPF and our controls are flexible. If anyone has other ideas, please feel free to post them.

Thanks!