请参阅 Windows Phone的启动，恢复和多任务处理 .

See Launching, Resuming, and Multitasking for Windows Phone.

花一点时间阅读文档几乎总是比让您发布问题并等待其他人为您阅读更快地获得答案.

A little time spent reading the documentation will almost always get you answers faster than posting a question and waiting for someone else to read it for you.