如何让超出父视图区域的子视图实现点击事件

在父视图重写hitTest:withEvent:方法，代码如下：

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {

    //CGRectMake(50, 50, 100, 100)是相对于该视图而言的

    if([self isLocationInRectWithPoint:point withRect:CGRectMake(50, 50, 100, 100)]){

        for(UIView *subview in self.subviews){

            if([self isLocationInRectWithPoint:point withRect:subview.frame]){

                return subview;

            }

        }

        return self;

    }

    return nil;

}

//判断点是否在一个区域里

- (BOOL)isLocationInRectWithPoint:(CGPoint)point withRect:(CGRect)rect {

    if(point.x >= rect.origin.x && point.x <= rect.origin.x+rect.size.width

       && point.y >= rect.origin.y && point.y <= rect.origin.y+rect.size.height){

        return YES;

    }

    return NO;

}

这时如果子视图在父视图区域之外也可以相应事件