本文轉載于Cocos2d-x v3.2學習筆記中的（九）事件分發機制（EventDispatcher）

EventDispatcher事件分發機制先創建事件，注冊到事件管理中心_eventDispatcher，通過發布事件得到響應進行回調，完成事件流。

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有五種不同的事件機制：

• EventListenerTouch 響應觸控事件

• EventListenerKeyboard 響應鍵盤事件

• EventListenerAcceleration 響應加速器事件

• EventListenMouse 響應鼠標事件

• EventListenerCustom 響應自定義的事件

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優先權：

1.優先級越低，越先響應事件

2.如果優先級相同，則上層的（z軸）先接收觸摸事件。

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事件監聽器的優先級：

1.addEventListenerWithSceneGraphPriority 的事件監聽器優先級是0，而且在 addEventListenerWithFixedPriority 中的事件監聽器的優先級不可以設置為 0，因為這個是保留給 SceneGraphPriority 使用的。

2.另外，有一點非常重要，FixedPriority listener添加完之后需要手動remove，而SceneGraphPriority listener是跟node綁定的，在node的析構函數中會被移除。移除方 法：dispatcher->removeEventListener(listener);

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事件管理單例獲取：

_eventDispatcher 是Node的屬性，通過它管理當前節點（場景、層、精靈等）的所有事件的分發。但它本身是一個單例模式值的引用，在Node的構造函數中，通過 Director::getInstance()->getEventDispatcher(); 獲取，有了這個屬性，就能方便的處理事件。

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觸摸事件

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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);//是否向下傳遞 ????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); 　　//判斷觸摸區域是否在目標上 ????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......"); }

鍵盤事件

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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!"); }

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鼠標事件

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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!"); }

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自定義事件

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//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); }

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加速器事件

除了觸摸，移動設備上一個很重要的輸入源是設備的方向，因此大多數設備都配備了加速計，用于測量設備靜止或勻速運動時所受到的重力方向。

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重力感應來自移動設備的加速計，通常支持X,Y和Z三個方向的加速度感應，所以又稱為三向加速計。在實際應用中，可以根據3個方向的力度大小來計算手機傾斜的角度或方向。

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加速計監聽器EventListenerAcceleration，其靜態create方法中有個Acceleration的參數。Acceleration是一個類，包含了加速計獲得的3個方向的加速度。

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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); }

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示例代碼

EventDispatcherTest.h

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#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 EventDispatcherTest.h

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EventDispatcherTest.cpp

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#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);//是否向下傳遞 ????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); } EventDispatcherTest.cpp

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【官方文檔】事件分發機制

轉載于:https://www.cnblogs.com/dudu580231/p/4565779.html

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