EventDispatcher事件分发机制先创建事件，注册到事件管理中心_eventDispatcher，通过发布事件得到响应进行回调，完成事件流。
有五种不同的事件机制：
EventListenerTouch 响应触控事件
EventListenerKeyboard 响应键盘事件
EventListenerAcceleration 响应加速器事件
EventListenMouse 响应鼠标事件
EventListenerCustom 响应自定义的事件
优先权：
1.优先级越低，越先响应事件
2.如果优先级相同，则上层的（z轴）先接收触摸事件。
事件监听器的优先级：
1.addEventListenerWithSceneGraphPriority 的事件监听器优先级是0，而且在 addEventListenerWithFixedPriority 中的事件监听器的优先级不可以设置为 0，因为这个是保留给 SceneGraphPriority 使用的。
2.另外，有一点非常重要，FixedPriority listener添加完之后需要手动remove，而SceneGraphPriority listener是跟node绑定的，在node的析构函数中会被移除。移除方法：dispatcher->removeEventListener(listener);
事件管理单例获取：
_eventDispatcher是Node的属性，通过它管理当前节点（场景、层、精灵等）的所有事件的分发。但它本身是一个单例模式值的引用，在Node的构造函数中，通过Director::getInstance()->getEventDispatcher(); 获取，有了这个属性，就能方便的处理事件。
触摸事件：
void EventDispatcherTest::funEventTouch(Sprite* sprite)
{
this->_eventDispatcher->removeAllEventListeners();
auto listener = EventListenerTouchOneByOne::create();
listener->onTouchBegan = CC_CALLBACK_2(EventDispatcherTest::onTouchBeganss,this);
listener->onTouchMoved = CC_CALLBACK_2(EventDispatcherTest::onTouchMovedss,this);
listener->onTouchEnded = CC_CALLBACK_2(EventDispatcherTest::onTouchEndedss,this);
listener->onTouchCancelled = CC_CALLBACK_2(EventDispatcherTest::onTouchCancelledss,this);
listener->setSwallowTouches(true);//是否向下传递
this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,sprite);
}
bool EventDispatcherTest::onTouchBeganss(Touch* touch,Event* ev)
{
auto target = static_cast<Sprite*>(ev->getCurrentTarget());
Vec2 locationInNode = target->convertToNodeSpace(touch->getLocation());
Size s = target->getContentSize();
Rect rect = Rect(0, 0, s.width, s.height);
//判断触摸区域是否在目标上
if (rect.containsPoint(locationInNode))
{
label->setString("onTouchBegan......");
target->setOpacity(180);
return true;
}
return false;
}
void EventDispatcherTest::onTouchMovedss(Touch* touch,Event* ev)
{
auto target = static_cast<Sprite*>(ev->getCurrentTarget());
target->setPosition(target->getPosition() + touch->getDelta());
label->setString("onTouchMoved......");
}
void EventDispatcherTest::onTouchEndedss(Touch* touch,Event* ev)
{
auto target = static_cast<Sprite*>(ev->getCurrentTarget());
target->setOpacity(255);
label->setString("onTouchEnded......");
}
void EventDispatcherTest::onTouchCancelledss(Touch* touch,Event* ev)
{
label->setString("onTouchCancelled......");
}
键盘事件
void EventDispatcherTest::funEventKeyboard()
{
this->_eventDispatcher->removeAllEventListeners();
auto listener = EventListenerKeyboard::create();
listener->onKeyPressed = CC_CALLBACK_2(EventDispatcherTest::onKeyPressedss,this);
listener->onKeyReleased = CC_CALLBACK_2(EventDispatcherTest::onKeyReleasedss,this);
this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,this);
}
void EventDispatcherTest::onKeyPressedss(EventKeyboard::KeyCode keycode,Event* ev)
{
char txt[100] = {};
sprintf_s(txt,"key %d is Pressed!",(int)keycode);
label->setString(txt);
}
void EventDispatcherTest::onKeyReleasedss(EventKeyboard::KeyCode keycode,Event* ev)
{
label->setString("key is Released!");
}
鼠标事件
void EventDispatcherTest::funEventMouse(Sprite* sprite)
{
this->_eventDispatcher->removeAllEventListeners();
auto listener = EventListenerMouse::create();
listener->onMouseDown = CC_CALLBACK_1(EventDispatcherTest::onMouseDownss,this);
listener->onMouseMove = CC_CALLBACK_1(EventDispatcherTest::onMouseMovess,this);
listener->onMouseUp = CC_CALLBACK_1(EventDispatcherTest::onMouseUpss,this);
listener->onMouseScroll = CC_CALLBACK_1(EventDispatcherTest::onMouseScrollss,this);
this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,sprite);
}
void EventDispatcherTest::onMouseDownss(Event* ev)
{
label->setString("onMouseDown!");
}
void EventDispatcherTest::onMouseMovess(Event* ev)
{
label->setString("onMouseMove!");
}
void EventDispatcherTest::onMouseUpss(Event* ev)
{
label->setString("onMouseUp!");
}
void EventDispatcherTest::onMouseScrollss(Event* ev)
{
label->setString("onMouseScroll!");
}
自定义事件
//自定義事件
funEventCustom();
//2秒後派發一次自定義事件，測試
scheduleOnce(schedule_selector(EventDispatcherTest::dispatcherCustomEvents),2.0f);
void EventDispatcherTest::funEventCustom()
{
auto listener = EventListenerCustom::create("custom_event_1",CC_CALLBACK_1(EventDispatcherTest::onEventCustom,this));
this->_eventDispatcher->addEventListenerWithFixedPriority(listener,1);//添加到事件分發器
}
void EventDispatcherTest::dispatcherCustomEvents(float at)
{
//派發事件custom_event_1 事件內容為字符串custom event test!
this->_eventDispatcher->dispatchCustomEvent("custom_event_1","custom event test!");
}
void EventDispatcherTest::onEventCustom(EventCustom* event)
{
auto data = static_cast<char*>(event->getUserData());
label->setString(data);
}
加速器事件
除了触摸，移动设备上一个很重要的输入源是设备的方向，因此大多数设备都配备了加速计，用于测量设备静止或匀速运动时所受到的重力方向。
重力感应来自移动设备的加速计，通常支持X,Y和Z三个方向的加速度感应，所以又称为三向加速计。在实际应用中，可以根据3个方向的力度大小来计算手机倾斜的角度或方向。
加速计监听器EventListenerAcceleration，其静态create方法中有个Acceleration的参数。Acceleration是一个类，包含了加速计获得的3个方向的加速度。
void EventDispatcherTest::funEventAcceleration()
{
//啟動硬件設備
Device::setAccelerometerEnabled(true);
auto listener = EventListenerAcceleration::create(CC_CALLBACK_2(EventDispatcherTest::onAcceleration,this));
this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,this);
}
void EventDispatcherTest::onAcceleration(Acceleration* acc,Event* event)
{
char str[100]={};
sprintf_s(str,"x:%2d,y:%2d,z:%2d,timestamp:%2d",acc->x,acc->y,acc->z,acc->timestamp);
log(str);
}
示例代码
#ifndef __EventDispatcherTest__ #define __EventDispatcherTest__ #include "cocos2d.h" USING_NS_CC; class EventDispatcherTest : public Layer { public: CREATE_FUNC(EventDispatcherTest); virtual bool init(); static Scene* createScene(); LabelTTF* label; void funEventTouch(Sprite* sprite); void funEventKeyboard(); void funEventMouse(Sprite* sprite); void funEventCustom(); void funEventAcceleration(); bool onTouchBeganss(Touch* touch,Event* ev); void onTouchMovedss(Touch* touch,Event* ev); void onTouchEndedss(Touch* touch,Event* ev); void onTouchCancelledss(Touch* touch,Event* ev); void onKeyPressedss(EventKeyboard::KeyCode keycode,Event* ev); void onKeyReleasedss(EventKeyboard::KeyCode keycode,Event* ev); void onMouseDownss(Event* ev); void onMouseMovess(Event* ev); void onMouseUpss(Event* ev); void onMouseScrollss(Event* ev); void dispatcherCustomEvents(float at); void onEventCustom(EventCustom* event); void onAcceleration(Acceleration* acc,Event* event); }; #endif
#include "EventDispatcherTest.h" Scene* EventDispatcherTest::createScene() { auto scene = Scene::create(); auto layer = EventDispatcherTest::create(); scene->addChild(layer); return scene; } bool EventDispatcherTest::init() { Size visibleSize = Director::getInstance()->getVisibleSize(); Vec2 origin = Director::getInstance()->getVisibleOrigin(); label = LabelTTF::create("Hello World", "Arial", 24); label->setPosition(Vec2(origin.x + visibleSize.width/2, origin.y + visibleSize.height - label->getContentSize().height)); this->addChild(label, 100); auto sprite = Sprite::create("MagentaSquare.png",Rect(0,0,100,100)); sprite->setPosition(visibleSize/2); this->addChild(sprite); //funEventTouch(sprite); //觸摸事件 //funEventKeyboard(); //鍵盤事件 //funEventMouse(sprite);//鼠標事件 //funEventAcceleration();//加速器事件 //自定義事件 funEventCustom(); //2秒後派發一次自定義事件，測試 scheduleOnce(schedule_selector(EventDispatcherTest::dispatcherCustomEvents),2.0f); return true; } void EventDispatcherTest::funEventTouch(Sprite* sprite) { this->_eventDispatcher->removeAllEventListeners(); auto listener = EventListenerTouchOneByOne::create(); listener->onTouchBegan = CC_CALLBACK_2(EventDispatcherTest::onTouchBeganss,this); listener->onTouchMoved = CC_CALLBACK_2(EventDispatcherTest::onTouchMovedss,this); listener->onTouchEnded = CC_CALLBACK_2(EventDispatcherTest::onTouchEndedss,this); listener->onTouchCancelled = CC_CALLBACK_2(EventDispatcherTest::onTouchCancelledss,this); listener->setSwallowTouches(true);//是否向下传递 this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,sprite); } bool EventDispatcherTest::onTouchBeganss(Touch* touch,Event* ev) { auto target = static_cast<Sprite*>(ev->getCurrentTarget()); Vec2 locationInNode = target->convertToNodeSpace(touch->getLocation()); Size s = target->getContentSize(); Rect rect = Rect(0, 0, s.width, s.height); if (rect.containsPoint(locationInNode)) { label->setString("onTouchBegan......"); target->setOpacity(180); return true; } return false; } void EventDispatcherTest::onTouchMovedss(Touch* touch,Event* ev) { auto target = static_cast<Sprite*>(ev->getCurrentTarget()); target->setPosition(target->getPosition() + touch->getDelta()); label->setString("onTouchMoved......"); } void EventDispatcherTest::onTouchEndedss(Touch* touch,Event* ev) { auto target = static_cast<Sprite*>(ev->getCurrentTarget()); target->setOpacity(255); label->setString("onTouchEnded......"); } void EventDispatcherTest::onTouchCancelledss(Touch* touch,Event* ev) { label->setString("onTouchCancelled......"); } void EventDispatcherTest::funEventKeyboard() { this->_eventDispatcher->removeAllEventListeners(); auto listener = EventListenerKeyboard::create(); listener->onKeyPressed = CC_CALLBACK_2(EventDispatcherTest::onKeyPressedss,this); listener->onKeyReleased = CC_CALLBACK_2(EventDispatcherTest::onKeyReleasedss,this); this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,this); } void EventDispatcherTest::onKeyPressedss(EventKeyboard::KeyCode keycode,Event* ev) { char txt[100] = {}; sprintf_s(txt,"key %d is Pressed!",(int)keycode); label->setString(txt); } void EventDispatcherTest::onKeyReleasedss(EventKeyboard::KeyCode keycode,Event* ev) { label->setString("key is Released!"); } void EventDispatcherTest::funEventMouse(Sprite* sprite) { this->_eventDispatcher->removeAllEventListeners(); auto listener = EventListenerMouse::create(); listener->onMouseDown = CC_CALLBACK_1(EventDispatcherTest::onMouseDownss,this); listener->onMouseMove = CC_CALLBACK_1(EventDispatcherTest::onMouseMovess,this); listener->onMouseUp = CC_CALLBACK_1(EventDispatcherTest::onMouseUpss,this); listener->onMouseScroll = CC_CALLBACK_1(EventDispatcherTest::onMouseScrollss,this); this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,sprite); } void EventDispatcherTest::onMouseDownss(Event* ev) { label->setString("onMouseDown!"); } void EventDispatcherTest::onMouseMovess(Event* ev) { label->setString("onMouseMove!"); } void EventDispatcherTest::onMouseUpss(Event* ev) { label->setString("onMouseUp!"); } void EventDispatcherTest::onMouseScrollss(Event* ev) { label->setString("onMouseScroll!"); } void EventDispatcherTest::funEventCustom() { auto listener = EventListenerCustom::create("custom_event_1",CC_CALLBACK_1(EventDispatcherTest::onEventCustom,this)); this->_eventDispatcher->addEventListenerWithFixedPriority(listener,1);//添加到事件分發器 } void EventDispatcherTest::dispatcherCustomEvents(float at) { //派發事件custom_event_1 事件內容為字符串custom event test! this->_eventDispatcher->dispatchCustomEvent("custom_event_1","custom event test!"); } void EventDispatcherTest::onEventCustom(EventCustom* event) { auto data = static_cast<char*>(event->getUserData()); label->setString(data); } void EventDispatcherTest::funEventAcceleration() { //啟動硬件設備 Device::setAccelerometerEnabled(true); auto listener = EventListenerAcceleration::create(CC_CALLBACK_2(EventDispatcherTest::onAcceleration,this)); this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,this); } void EventDispatcherTest::onAcceleration(Acceleration* acc,Event* event) { char str[100]={}; sprintf_s(str,"x:%2d,y:%2d,z:%2d,timestamp:%2d",acc->x,acc->y,acc->z,acc->timestamp); log(str); }