title: Programmatically close ListPicker from WP7 Silverlight Toolkit
body: <p>My app is being rejected from the Marketplace because of requirement 5.2.4.c (back button must close menu or dialog and cancel back navigation). I'm using a ListPicker from the Silverlight Toolkit and that's what's causing the failure: pressing the back button when the ListPicker is open goes back instead of closing the ListPicker and cancelling back navigation.</p>
  
  <p>This seems simple enough to fix: if the user presses the back button and the ListPicker is open, I close it and cancel back navigation. However, I haven't seen a way of programatically either detecting whether a ListPicker is open, or closing a ListPicker.</p>
  
  <p>Am I missing something? How could I fix this bug?</p>