改变tabbar的高度做法

 UITabBarController *tabBarController =[[UITabBarController alloc] init];

     CGRect frame = self.window.bounds;

     tabBarController.tabBar.frame = CGRectMake(, CGRectGetHeight(frame) - , CGRectGetWidth(frame), CGRectGetHeight(frame));

     UIView *transitionView = [[tabBarController.view subviews] objectAtIndex:];

     frame.size.height = CGRectGetHeight(frame) - ;

     transitionView.frame = frame;