为什么调用UIWidget的clone比直接widgetFromJsonFile还慢

Studio
#1 
CCTime::gettimeofdayCocos2d(&startval, NULL);

    UIWidget* pWidget = GUIReader::shareReader()->widgetFromJsonFile("formationitembox.ExportJson");
    UILayer* pUI = UILayer::create();
    pUI->addChild(pWidget);
    this->addChild(pUI, 0);

    CCTime::gettimeofdayCocos2d(&endval, NULL);
    double del = CCTime::timersubCocos2d(&startval,&endval);
    CCLOG("%f",del);

    CCTime::gettimeofdayCocos2d(&startval, NULL);
    for (int i=0; i<10; i++)
    {
        pWidget->clone();
    }
    CCTime::gettimeofdayCocos2d(&endval, NULL);
    del = CCTime::timersubCocos2d(&startval,&endval);
    CCLOG("%f",del);

    CCTime::gettimeofdayCocos2d(&startval, NULL);
    for (int i=0; i<10; i++)
    {
        UIWidget* pWidget = GUIReader::shareReader()->widgetFromJsonFile("formationitembox.ExportJson");
    }
    CCTime::gettimeofdayCocos2d(&endval, NULL);
    del = CCTime::timersubCocos2d(&startval,&endval);
    CCLOG("%f",del);

三个时间分别是
247.748000 //第一次加载json
957.473000 //clone10次

760.041000 //加载10次

#2

感谢楼主反馈，我们再测试下这里的效率