问题
With a trick it is possible to run the app, if the home button is pressed. In the background mode, no request with RKRequestQueue will be send, so the app receive no response from backande server and the app can't update the data.
回答1:
This is standard behavior. When the app becomes active (i.e. is running and no longer in the background), you may want to implement the -(void)applicationDidBecomeActive:(UIAplication *)application method in your application delegate which would resume where you left off, or to resubmit your request, restart your request queue, whatever your situation requires.
来源：https://stackoverflow.com/questions/8519664/no-request-will-send-if-app-is-in-background-mode-optionen