cocos2d-x 场景间传值

void A::onClick(CCObject * pObject)
{
    // -----------------1.场景切换----------------------

    CCScene * scene = B::scene();
    B * layer = (B*)(scene->getChildren()->objectAtIndex(0));
    layer->value = "要传的值";
    CCDirector::sharedDirector()->replaceScene(scene );
}

class B: public cocos2d::CCLayer
{
public:
    virtual bool init();
    virtual void onEnter();
    static CCScene * scene();

    CCString value;

    CREATE_FUNC(B);
};

void B::onEnter()
{
    CCLayer::onEnter();
    CCLog(value.getCString());
}