ListView in cocos2dx v3.3 - Zoom item center of screen

I’m developing a game in which I want to add a ListView, but I need to zoom (or scale) item of listview which is center on screen.
My code is following

 ui::ListView* _mainScroll;   
 Size scrollSize = Size(visibleSize.width*.2, visibleSize.height*.4);

    _mainScroll = ui::ListView::create();
    for (int i=1; i<=100; i++)
    {
    	__String *name= __String::createWithFormat("CloseNormal.png", i);

    	ui::Button* model = Button::create();
    	model->setTag(i);
    	model->loadTextures (name->getCString(), name->getCString(), "");
    	model->addTouchEventListener(CC_CALLBACK_2(HelloWorld::lvTouchOnMainTray, this));
    	_mainScroll->pushBackCustomItem(model);
    }
    _mainScroll->setItemsMargin(20.0);
    _mainScroll->setGravity(ListView::Gravity::CENTER_VERTICAL);
    _mainScroll->setSize(scrollSize);
    _mainScroll->setBackGroundColorType(ListView::BackGroundColorType::NONE);
    _mainScroll->setPosition(Vec2(visibleSize.width*.48, visibleSize.height*.3));
    _mainScroll->setDirection(ListView::Direction::VERTICAL);
    addChild(_mainScroll);

I searched a lot on google, stackoverflow and cocos forum too, but I didn’t found solution of my question.
Sorry for bad English.
Thanx in advance.