Cocos2d-x实例：设置背景音乐与音效- AppDelegate实现

为了进一步了解背景音乐和音效播放的，我们通过一个实例给大家介绍一下。例如以下图所看到的有两个场景：HelloWorld和Setting。在HelloWorld场景点击“游戏设置”菜单能够切换到Setting场景，在Setting场景中能够设置是否播放背景音乐和音效，设置完毕后点击“OK”菜单能够返回到HelloWorld场景。 

#ifndef  _APP_DELEGATE_H_
#define  _APP_DELEGATE_H_


#include "cocos2d.h"
#include "SimpleAudioEngine.h"											①


using namespace CocosDenshion;											②
class  AppDelegate : private cocos2d::Application
{
public:
    AppDelegate();
    virtual ~AppDelegate();


    virtual bool applicationDidFinishLaunching();
    virtual void applicationDidEnterBackground();
    virtual void applicationWillEnterForeground();
};


#endif // _APP_DELEGATE_H_

#include "AppDelegate.h"
#include "HelloWorldScene.h"


USING_NS_CC;


AppDelegate::AppDelegate() {


}


AppDelegate::~AppDelegate() 
{
}


bool AppDelegate::applicationDidFinishLaunching() {								①
… …
    // run
    director->runWithScene(scene);
	
	//初始化 背景音乐
	SimpleAudioEngine::getInstance()->preloadBackgroundMusic("sound/Jazz.mp3");		②
	SimpleAudioEngine::getInstance()->preloadBackgroundMusic("sound/Synth.mp3");		③
	//初始化 音效
	SimpleAudioEngine::getInstance()->preloadEffect("sound/Blip.wav");					④


    return true;
}


void AppDelegate::applicationDidEnterBackground() {								⑤
    Director::getInstance()->stopAnimation();


    SimpleAudioEngine::getInstance()->pauseBackgroundMusic();					⑥
}


void AppDelegate::applicationWillEnterForeground() {								⑦
    Director::getInstance()->startAnimation();


    SimpleAudioEngine::getInstance()->resumeBackgroundMusic();					⑧
}

第⑤行代码是声明applicationDidEnterBackground()是游戏进入到后天时候调用函数，在这个函数中须要停止动画和暂停背景音乐播放。第⑦行代码是声明applicationWillEnterForeground()是游戏从后天回到前台时候调用，在这个函数中须要继续动画和背景音乐播放。