how can I use nstimer in background

Question

如何在后台使用NSTimer和applicationDidEnterBackground方法来调用locationManager函数？

Answer 1

Why would you need a timer? If you set your delegate to receive the callbacks from location updates, you won't need a timer. If you need active location tracking, you will be taking a huge battery hit if it runs for extended periods of time. You would be better off when you enter background to switch to -monitorForSignificantLocationChanges instead. Register your AppDelegate as as the Location Manager Delegate and just do what you need to do from the call backs.