UIApplicationState state = [UIApplication sharedApplication].applicationState;
BOOL result = (state ==UIApplicationStateBackground);
NSLog(@"是后臺(tái)運(yùn)行: %@",result?@"YES":@"NO");
UIApplicationState state2 = [UIApplication sharedApplication].applicationState; ?
BOOL result2 = (state2 ==UIApplicationStateActive);
NSLog(@"是前臺(tái)運(yùn)行: %@",result2?@"YES":@"NO");