滚动层方面的问题

Cocos2d-x
#1

问下 我cocostudio导出的资源加载道程序中 怎么没有滚动的效果啊 程序如下：

    ui::ScrollView* scrollView = ui::ScrollView::create();
    scrollView->setDirection(SCROLLVIEW_DIR_BOTH);
    scrollView->setTouchEnabled(true);
    scrollView->setBounceEnabled(true);
    scrollView->setBackGroundImageScale9Enabled(true);
    scrollView->setBackGroundImage("cocosui/edit.png");
    scrollView->setSize(Size(210, 122.5));
    Size backgroundSize = background->getContentSize();
    scrollView->setPosition(Point((widgetSize.width - backgroundSize.width) / 2.0f +
                                (backgroundSize.width - scrollView->getSize().width) / 2.0f,
                                (widgetSize.height - backgroundSize.height) / 2.0f +
                                (backgroundSize.height - scrollView->getSize().height) / 2.0f));
    ImageView* imageView = ImageView::create();
    imageView->setTouchEnabled(true);
    imageView->loadTexture("image.png");
    scrollView->addChild(imageView);
    
    scrollView->setInnerContainerSize(imageView->getContentSize());
    Size innerSize = scrollView->getInnerContainerSize();
    imageView->setPosition(Point(innerSize.width / 2.0f, innerSize.height / 2.0f));
    
    _uiLayer->addChild(scrollView); 不知是怎么回事？新手求解！