隐藏Tabbar

• (void)hideTabBar {
  if (self.tabBarController.tabBar.hidden == YES) {
  return;
  }
  UIView *contentView;
  if ( [[self.tabBarController.view.subviews objectAtIndex:0] isKindOfClass:[UITabBar class]] )
  contentView = [self.tabBarController.view.subviews objectAtIndex:1];
  else
  contentView = [self.tabBarController.view.subviews objectAtIndex:0];
  contentView.frame = CGRectMake(contentView.bounds.origin.x, contentView.bounds.origin.y, contentView.bounds.size.width, contentView.bounds.size.height + self.tabBarController.tabBar.frame.size.height);
  self.tabBarController.tabBar.hidden = YES;

}