Place opacityMask over panorama background, but not its contents

I want to create a mask effect so I place a mask over my panorama page, but this would place a mask on开发者_高级运维 my entire screen. How can I make it so that it would only place on top of my panorama background but under my panoramaitems?

You could retemplate the the Panorama control to add the mask over the background image.

I've found some issues with doing this in Mango though and so have chosen to manipulate the background image directly. This also led to code which was simpler to follow. (In my opinion.)