title: C# XNA Windows Phone 7 game: how to know which objects are pressed
body: <p>Say I have multiple objects laying on each other, if I click on one of them, the coordinates returned from TouchPanel.GetState() would not able to tell me which object is selected. The object is not necessary the top most one. In this case, do I organize the list of objects so that sorted by Z value and compare Rectangles from top to bottom. Is this right way to do that? Or if there is any UI framework providing some sort of component to inherit so that the object will have callback when there is external event happening?</p>