• 事件监听器封装了事件处理代码
• 事件派发器通知用户事件的监听器
• 事件对象包含了事件的相关信息

• EventListenerTouch- responds to touch events
• EventListenerKeyboard- responds to keyboard events
• EventListenerAcceleration- reponds to accelerometer events
• EventListenMouse- responds to mouse events
• EventListenerCustom- responds to custom events

   auto sprite1 = Sprite::create("Images/CyanSquare.png");
   sprite1->setPosition(origin+Point(size.width/2, size.height/2) + Point(-80, 80));
   addChild(sprite1,153)">10);
 
   auto sprite2 = Sprite::create("Images/MagentaSquare.png");
   sprite2->setPosition(origin+Point(size.width/2));
   addChild(sprite2,153)">20);
 
   auto sprite3 = Sprite::create("Images/YellowSquare.png");
   sprite3->setPosition(Point(0,153)">0));
   sprite2->addChild(sprite3,153)">1);

    //Create a "one by one" touch event listener (processes one touch at a time)
    auto listener1 = EventListenerTouchOneByOne::create();
    // When "swallow touches" is true,then returning 'true' from the onTouchBegan method will "swallow" the touch event,preventing other listeners from using it.
    listener1->setSwallowTouches(true);
 
    // Example of using a lambda expression to implement onTouchBegan event callback function
    listener1->onTouchBegan = [](Touch* touch, Event* event){
        // event->getCurrentTarget() returns the *listener's* sceneGraPHPriority node.
        auto target = static_cast<Sprite*>(event->getCurrentTarget());
 
        //Get the position of the current point relative to the button
        Point locationInNode = target->convertToNodeSpace(touch->getLocation());
        Size s = target->getContentSize();
        Rect rect = Rect(s.width, s.height);
 
        //Check the click area
        if (rect.containsPoint(locationInNode))
        {
            log("sprite began... x = %f,y = %f", locationInNode.x, locationInNode.y);
            target->setOpacity(180);
            return true;
        }
        return false;
    };
 
    //Trigger when moving touch
    listener1->onTouchMoved = [](Touch* touch, Event* event){
        auto target = static_cast<Sprite*>(event->getCurrentTarget());
        //Move the position of current button sprite
        target->setPosition(target->getPosition() + touch->getDelta());
    };
 
    //Process the touch end event
    listener1->onTouchEnded = [=](Touch* touch, Event* event){
        auto target = static_cast<Sprite*>(event->getCurrentTarget());
        log("sprite onTouchesEnded.. ");
        target->setOpacity(255);
        //Reset zOrder and the display sequence will change
        if (target == sprite2)
        {
            sprite1->setZOrder(100);
        }
        else if(target == sprite1)
        {
            sprite1->setZOrder(0);
        }
    };

//Add listener
    _eventDispatcher->addEventListenerWithSceneGraPHPriority(listener1, sprite1);
    _eventDispatcher->addEventListenerWithSceneGraPHPriority(listener1->clone(), sprite2);
    _eventDispatcher->addEventListenerWithSceneGraPHPriority(listener1->clone(), sprite3);

1. 一个sprite可以将事件监听器添加到SceneGraPHPriority的事件派发器（场景图优先事件派发器），一个事件触发时，回调函数将按它们的绘制次序来调用，即在场景前的优先调用；
2. 处理事件逻辑时，根据不同的情景来调用回调（识别点击区域，设置点击元素的透明度）来播放点击效果。
3. 
   

• FixedPriority 整形值。低权值的事件监听器将优于高权值的事件监听器
• SceneGraPHPriority Node的指针。Node的z顺序高的（绘制于顶部的）节点将优于z顺序低的节点。这将保证了诸如触碰事件的自顶向下传播

//Initializing and binding 
    auto listener = EventListenerKeyboard::create();
    listener->onKeyPressed = CC_CALLBACK_2(KeyboardTest::onKeyPressed, this);
    listener->onKeyReleased = CC_CALLBACK_2(KeyboardTest::onKeyReleased, this);
 
    _eventDispatcher->addEventListenerWithSceneGraPHPriority(listener, this);
 
    // Implementation of the keyboard event callback function prototype
    void KeyboardTest::onKeyPressed(EventKeyboard::KeyCode keyCode, Event* event)
    {
        log("Key with keycode %d pressed", keyCode);
    }
 
    void KeyboardTest::onKeyReleased(EventKeyboard::KeyCode keyCode,68)">"Key with keycode %d released", keyCode);
    }   

    auto listener = EventListenerAcceleration::create(CC_CALLBACK_2(AccelerometerTest::onAcceleration, this));
    _eventDispatcher->addEventListenerWithSceneGraPHPriority(listener,136)">// Implementation of the accelerometer callback function prototype
    void AccelerometerTest::onAcceleration(Acceleration* acc, Event* event)
    {
        //  Processing logic here 
    }

    _mouseListener = EventListenerMouse::create();
    _mouseListener->onMouseMove = CC_CALLBACK_1(MouseTest::onMouseMove, this);
    _mouseListener->onMouseUp = CC_CALLBACK_1(MouseTest::onMouseUp, this);
    _mouseListener->onMouseDown = CC_CALLBACK_1(MouseTest::onMouseDown, this);
    _mouseListener->onMouseScroll = CC_CALLBACK_1(MouseTest::onMouseScroll, this);
 
    _eventDispatcher->addEventListenerWithSceneGraPHPriority(_mouseListener, this);

void MouseTest::onMouseDown(Event *event)
{
    EventMouse* e = (EventMouse*)event;
    string str = "Mouse Down detected,Key: ";
    str += tostr(e->getMouseButton());
    // ...
}
 
void MouseTest::onMouseUp(Event *event)
{
    EventMouse* e = (EventMouse*)event;
    string str = "Mouse Up detected,136)">void MouseTest::onMouseMove(Event *event)
{
    EventMouse* e = (EventMouse*)event;
    string str = "MousePosition X:";
    str = str + tostr(e->getCursorX()) + " Y:" + tostr(e->getCursorY());
    void MouseTest::onMouseScroll(Event *event)
{
    EventMouse* e = (EventMouse*)event;
    string str = "Mouse Scroll detected,X: ";
    str = str + tostr(e->getScrollX()) + " Y: " + tostr(e->getScrollY());
    // ...
}

    _listener = EventListenerCustom::create("game_custom_event1", [=](EventCustom* event){
        std::string str("Custom event 1 received,");
        char* buf = static_cast<char*>(event->getUserData());
        str += buf;
        str += " times";
        statusLabel->setString(str.c_str());
    });
 
    _eventDispatcher->addEventListenerWithFixedPriority(_listener,153)">1);

    static int count = 0;
    ++count;
    char* buf = new char[10];
    sprintf(buf, "%d", count);
    EventCustom event("game_custom_event1");
    event.setUserData(buf);
    _eventDispatcher->dispatchEvent(&event);
    CC_SAFE_DELETE_ARRAY(buf);

    _eventDispatcher->removeEventListener(listener);

    _eventDispatcher->removeAllEventListeners();