UIView 视图方法

(void)removeFromSuperview;将视图从父视图中移除

(void)insertSubview:(UIView *)view atIndex:(NSInteger)index;插入一个视图到指定位置,视图越在下面，index越小

(void)exchangeSubviewAtIndex:(NSInteger)index1 withSubviewAtIndex:(NSInteger)index2;将index1和index2位置的两个视图互换位置

(void)addSubview:(UIView *)view;添加视图到父视图

(void)insertSubview:(UIView *)view belowSubview:(UIView *)siblingSubview;插入视图到指定视图的下面

(void)insertSubview:(UIView *)view aboveSubview:(UIView *)siblingSubview;插入视图到指定视图上面

(void)bringSubviewToFront:(UIView *)view;把视图移到最顶层

(void)sendSubviewToBack:(UIView *)view;把视图移到最底层

(UIView *)viewWithTag:(NSInteger)tag; 根据视图的tag属性找到搜索视图