1 点击子view 会出发父view的此方法
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
解决方法，在子view中实现此方法可阻断父视图响应此方法
3.取消延迟方法执行
(void)performSelector:(SEL)aSelector withObject:(nullable id)anArgument afterDelay:(NSTimeInterval)delay inModes:(NSArray<NSRunLoopMode> *)modes;
(void)performSelector:(SEL)aSelector withObject:(nullable id)anArgument afterDelay:(NSTimeInterval)delay
performSelector N秒钟之后 执行方法
(void)cancelPreviousPerformRequestsWithTarget:(id)aTarget selector:(SEL)aSelector object:(nullable id)anArgument;
(void)cancelPreviousPerformRequestsWithTarget:(id)aTarget
cancelPreviousPerformRequestsWithTarget：取消performSelector方法注册过的方法，就是说当上面这个方法正在运行，比如希望5秒钟之后执行某一个方法，但是没到5秒钟的情况下取消performSelector，就是用cancelPreviousPerformRequestsWithTarget方法来实现的
