[[NSNotificationCenter defaultCenter] addObserver:self

                                                 selector:@selector(didChangeStatusBarFrame:)                                                      name:UIApplicationWillChangeStatusBarFrameNotification object:nil];

 

 

#pragma mark - notif status bar

- (void)didChangeStatusBarFrame:(NSNotification *)notification

{

    NSValue *statusBarFrameValue = [notification.userInfo valueForKey:UIApplicationStatusBarFrameUserInfoKey];

   

    // TODO: react on changes of status bar height (e.g. incoming call, tethering, ...)

    // NSLog(@"Status bar frame changed: %@", NSStringFromCGRect([statusBarFrameValue CGRectValue]));

   

}

 

模拟器中可以模拟这种情况，如下图：