hide statusbar on ios7

hideStatusbar.m

//viewDidLoad
if ([self respondsToSelector:@selector(setNeedsStatusBarAppearanceUpdate)]) {
    // for iOS 7
    [self prefersStatusBarHidden];
    [self performSelector:@selector(setNeedsStatusBarAppearanceUpdate)];
} else {
    // for under iOS 6
    [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationSlide];
}

//define method
- (BOOL)prefersStatusBarHidden
{
    return YES;
}