Chapter 10. The Application Life Cycle
This chapter deals with an area that you will almost certainly want to factor into your game in order for it to work as your users will expect. It covers what happens when your game loses focus on the device.
One of the more controversial decisions that Microsoft made about the Windows Phone 7 operating system is regarding its multitasking capabilities. Clearly, it is capable of multitasking, and some system applications run in the background the whole time, but third-party applications such as those that we can write are not permitted to multitask. When they lose focus, they completely stop executing.
The situation is slightly worse even than this; they don't simply stop executing, but they are actually closed. ...