- (void) hideTabBar:(BOOL) hidden{
   
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0];
    
    for(UIView *view in self.tabBarController.view.subviews)
    {
        if([view isKindOfClass:[UITabBar class]])
        {
            if (hidden) {
                [view setFrame:CGRectMake(view.frame.origin.x, 460, view.frame.size.width, view.frame.size.height)];
            } else {
                [view setFrame:CGRectMake(view.frame.origin.x, 460-49, view.frame.size.width, view.frame.size.height)];
            }
        }
        else
        {
            if (hidden) {
                [view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 460)];
            } else {
                [view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 460-49)];
            }
        }
    }
   
    [UIView commitAnimations];
}

摘自 shijiucdy的專欄