Dave has put together a great set of Silverlight controls written in C# that include layout containers a textbox with text selection.  The controls in the package are:

  • Layout framework
  • LayoutControl and LayoutContainerControl base control classes
  • Border
  • StackPanel
  • Grid
  • Label
  • Button (XAML courtesy of Mike Harsh)
  • TextBox

More information and source are in Dave's post.  Click the image below to run the sample.