I wrote a routine that uses a richtextbox to allow the user to enter formatted text. However for some reason it doesn't capture the delete key (a character is not deleted). THe macro just lets it fall through to Revit which starts the erase command. I've tried setting the KeyPreview of the window form to TRUE but this had no affect.

If I create a simple windows app with a richtextbox I notice the default behaviour is to capture the delete key and delete the character. So I'm thinking there is something in the Revit API that is altering this behaviour.

Does anyone have any ideas how to make the delete key work?