-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
   
    int count = (int)self.subviews.count;
    for (int i=count-1; i>=0; i--) {

        UIView *subView = self.subviews[i];

       // 点击事件作用在子控件上面， 返回点击点
        CGPoint isPoint = [self convertPoint:point toView:subView];
  // 获取到被点击的视图
        UIView *aView = [subView hitTest:isPoint withEvent:event];

        if (aView) {
            return aView;
        }
    }
    return self;
}