Can a double-tap gesture be used on an Entry control so as to do something other than edit the text?

I have an Entry control on a form that I can type a date into which is validated by a behavior and that works fine. I also have an invisible (to save screen real estate) DatePicker on the form that I would like to show itself (by giving it focus) if I double-click on the Entry control (I've added a 2-tap gesture to it) so that the user can pick a date rather than type one. The problem is that unless I'm doing something wrong, both a single- and double-tap gesture just allow the user to edit the text content as normal. Should it be possible to detect a double-tap on an Entry control too? Or do I need to create a custom control?