您可以按计划使用后台任务，且间隔时间不得超过15分钟.这些任务被设计为由与您的应用程序分开的操作系统来运行，因此，如果这些任务未处于活动状态或未打开，则将被执行. 这是有关后台任务入门的详细博客文章:

You can use a background task on a schedule for an interval for anything greater than 15 mins. The tasks are designed to be run by the OS separate to your application, so will be executed if it is not active or open. Here is a detailed blog post on getting started with background tasks: http://www.silverlightshow.net/items/Windows-8-metro-make-your-app-alive-with-background-tasks.aspx