问题
When an app is not currently "front and center" in Win8, it is suspended. Does this preclude keeping the app explicitly alive in the background, such as in an email client, using async operations to poll the mail server for new messages, and download them (and then update the Tile with count of new messages)?
If this is not possible (a suspended app cannot perform background processing, or cannot force the system to allow it to stay active, albeit not visible), what would be the workaround - a separate Windows Service?
回答1:
You should look into background tasks. There is a whitepaper here.
来源：https://stackoverflow.com/questions/11819882/can-developers-force-the-system-to-prevent-metro-apps-from-being-suspended-w