Background sync in iOS7

问题:

We have to develop an app which will support data sync operations at some time interval, whether the app is in foreground or in background.

I want to know that in iOS7…

• is it possible to sync data (i.e. call web services) while the app is in background?
• can we access SQLite data base file/can we do DB operations while the app is in background?
• can we run timers in background?
• can we show alerts about some updates while the app is in background?

Thanks in advance.

回答1:

1. Yes, it is.
2. Yes, you can.
3. Sometimes, but you shouldn't.
4. Yes, you can.

Go and research iOS 7 background operations. Talk of using timers and background operations at some time interval indicate you're approaching the problem in a way that won't work. While the answer to most of your questions is yes, your approach is probably no...

Start with application:performFetchWithCompletionHandler:.