UIButton超出父view的显示范围后，不响应点击事件

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
// 当前坐标系上的点转换到按钮上的点
CGPoint btnP = [self convertPoint:point toView:self.twoView];

// 判断点在不在按钮上
if ([self.twoView pointInside:btnP withEvent:event]) {
// 点在按钮上
return self.twoView;
}else{
return [super hitTest:point withEvent:event];
}
}