cocos2d-x之为label添加事件监听器，单点触摸

cocos2d-x之为label添加事件监听器，单点触摸

在bool HelloWorld::init()

//获取可见区域的大小
    Size visibleSize = Director::getInstance()->getVisibleSize();
    //定义一个文本，显示内容
    auto label = LabelTTF::create("Chick me", "Courier", 30);
    //定义label的位置
    label->setPosition(Point(visibleSize.width/2,visibleSize.height/2));
    addChild(label);//将label添加进去
    //EventListenerTouchOneByOne表示一个接一个的触发，每次触摸只能监听到一个触摸点
    auto listener = EventListenerTouchOneByOne::create();
    //onTouchBegan表示开始触摸的事件
    listener->onTouchBegan = [](Touch *t, Event *e){
        
        log("onTouchBegan");
        
        return false;
    };
    //getEventDispatcher获取事件的派发器，
    //addEventListenerWithSceneGraphPriority(事件, 节点);添加事件监听器
    Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, label);