Cocos2d-x实例：设置背景音乐与音效-HelloWorld场景实现

HelloWorld场景就是游戏中的主菜单场景。HelloWorld.h文件代码如下：

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#define __HELLOWORLD_SCENE_H__

#include "cocos2d.h"

#include "SimpleAudioEngine.h" ①

#include "SettingScene.h"

class HelloWorld : public cocos2d::Layer

{

public:

static cocos2d::Scene* createScene();

virtual bool init(); ②

virtual void onEnter();

virtual void onEnterTransitionDidFinish();

virtual void onExit();

virtual void onExitTransitionDidStart();

virtual void cleanup(); ③

void menuItemHelpCallback(cocos2d::Ref* pSender);

void menuItemStartCallback(cocos2d::Ref* pSender);

void menuItemSettingCallback(cocos2d::Ref* pSender);

CREATE_FUNC(HelloWorld);

};

bool HelloWorld::init()

{

if ( !Layer::init() )

{

return false;

}

log("HelloWorld init");

Size visibleSize = Director::getInstance()->getVisibleSize();

Point origin = Director::getInstance()->getVisibleOrigin();

Sprite *bg = Sprite::create("background.png");

bg->setPosition(Point(origin.x + visibleSize.width/2,

origin.y + visibleSize.height /2));

this->addChild(bg);

//开始精灵

Sprite *startSpriteNormal = Sprite::create("start-up.png");

Sprite *startSpriteSelected = Sprite::create("start-down.png");

MenuItemSprite *startMenuItem = MenuItemSprite::create(startSpriteNormal,

startSpriteSelected,

CC_CALLBACK_1(HelloWorld::menuItemStartCallback, this));

startMenuItem->setPosition(Director::getInstance()->convertToGL(Point(700, 170)));

// 设置图片菜单

MenuItemImage *settingMenuItem = MenuItemImage::create(

"setting-up.png",

"setting-down.png",

CC_CALLBACK_1(HelloWorld::menuItemSettingCallback, this));

settingMenuItem->setPosition(Director::getInstance()->convertToGL(Point(480, 400)));

// 帮助图片菜单

MenuItemImage *helpMenuItem = MenuItemImage::create(

"help-up.png",

"help-down.png",

CC_CALLBACK_1(HelloWorld::menuItemHelpCallback, this));

helpMenuItem->setPosition(Director::getInstance()->convertToGL(Point(860, 480)));

Menu* mu = Menu::create(startMenuItem, settingMenuItem, helpMenuItem, NULL);

mu->setPosition(Point::ZERO);

this->addChild(mu);

return true;

}

void HelloWorld::menuItemSettingCallback(Ref* pSender)

{

auto sc = Setting::createScene();

auto reScene = TransitionJumpZoom::create(1.0f, sc);

Director::getInstance()->pushScene(reScene);

SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav"); ②

}

void HelloWorld::menuItemHelpCallback(Ref* pSender)

{

MenuItem* item = (MenuItem*)pSender;

log("Touch Help %p", item);

SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav"); ③

}

void HelloWorld::menuItemStartCallback(Ref* pSender)

{

MenuItem* item = (MenuItem*)pSender;

log("Touch Start %p", item);

SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav"); ④

}

void HelloWorld::onEnter()

{

Layer::onEnter();

log("HelloWorld onEnter");

}

void HelloWorld::onEnterTransitionDidFinish()

{

Layer::onEnterTransitionDidFinish();

log("HelloWorld onEnterTransitionDidFinish");

//播放

SimpleAudioEngine::getInstance()->playBackgroundMusic("sound/Jazz.mp3", true); ⑤

}

void HelloWorld::onExit()

{

Layer::onExit();

log("HelloWorld onExit");

}

void HelloWorld::onExitTransitionDidStart()

{

Layer::onExitTransitionDidStart();

log("HelloWorld onExitTransitionDidStart");

}

void HelloWorld::cleanup()

{

Layer::cleanup();

log("HelloWorld cleanup");

//停止

SimpleAudioEngine::getInstance()->stopBackgroundMusic("sound/Jazz.mp3"); ⑥

}

上述代码第①行using namespace CocosDenshion是使用命名空间CocosDenshion，它是CocosDenshion引擎所需要的。代码②、③、④行SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav")是在点击菜单时候播放音效。第⑤行代码是onEnterTransitionDidFinish()函数中播放背景音乐。第⑥行代码是cleanup()函数中停止播放背景音乐。

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