cocos3.X拖动精灵移动

1、 创建一个精灵sprite；

2、一个触摸事件 listener ，设置listener的onTouchBegan,onTouchMoved,onTouchEnded;

3、将sprite 和 listener关联起来。

	Sprite* sprite1 = Sprite::create("pk.png");
	this->addChild(sprite1,0);
	sprite1->setPosition(ccp(300,400));
	sprite1->setTag(1);

	Sprite*  sprite2 = Sprite::create("pk.png");
	this->addChild(sprite2,0);
	sprite2->setPosition(ccp(200,400));
	sprite2->setTag(0);

	Sprite*  sprite3 = Sprite::create("pk.png");
	this->addChild(sprite3,0);
	sprite3->setPosition(ccp(400,400));
	sprite3->setTag(0);


	auto listener1 = EventListenerTouchOneByOne::create();//创建一个触摸监听
 	listener1->setSwallowTouches(true); //设置是否想下传递触摸

	//通过 lambda 表达式 直接实现触摸事件的回掉方法
	listener1->onTouchBegan = [](Touch* touch,Event* event){
		auto target = static_cast<Sprite*>(event->getCurrentTarget());

		Point locationInNode = target->convertToNodeSpace(touch->getLocation());
		Size s = target->getContentSize();
		Rect rect = Rect(0,s.width,s.height);

		if (rect.containsPoint(locationInNode))
		{
			log("sprite began... x = %f,y = %f",locationInNode.x,locationInNode.y);
			target->setOpacity(180);
			return true;
		}
		return false;
	};

	listener1->onTouchMoved = [](Touch* touch,Event* event){
		auto target = static_cast<Sprite*>(event->getCurrentTarget());
		target->setPosition(target->getPosition() + touch->getDelta());
	};

	listener1->onTouchEnded = [=](Touch* touch,Event* event){
		auto target = static_cast<Sprite*>(event->getCurrentTarget());
		log("sprite onTouchesEnded.. ");
		target->setOpacity(255);
	};

	_eventDispatcher->addEventListenerWithSceneGraphPriority(listener1,sprite1);
	_eventDispatcher->addEventListenerWithSceneGraphPriority(listener1->clone(),sprite2);
	_eventDispatcher->addEventListenerWithSceneGraphPriority(listener1->clone(),sprite3);

如果想实现多个精灵拖动，使用clone方法