设置场景（Setting），Setting.h文件代码如下：
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#ifndef __Setting_SCENE_H__
#define __Setting_SCENE_H__
#include "cocos2d.h"
#include "SimpleAudioEngine.h"
class Setting : public cocos2d::Layer
{
bool isEffect; ①
public:
static cocos2d::Scene* createScene();
virtual bool init();
virtual void onEnter();
virtual void onEnterTransitionDidFinish();
virtual void onExit();
virtual void onExitTransitionDidStart();
virtual void cleanup();
void menuSoundToggleCallback(cocos2d::Ref* pSender);
void menuMusicToggleCallback(cocos2d::Ref* pSender);
void menuOkCallback(cocos2d::Ref* pSender);
CREATE_FUNC(Setting);
};
#endif // __Setting_SCENE_H__
#define __HELLOWORLD_SCENE_H__
上述代码第①是定义布尔类型成员变量isEffect，它用来保存现在是否允许音效，事实上是否允许音效和背景音乐播放状态应该持久化到文件中，由于我们还没有介绍数据持久化，所以我们采用isEffect变量记录状态，当我们在后面的章节学习完成数据持久化后，再保存它们状态。其它的代码与HelloWorld场景代码非常相似，这里不再赘述。Setting.cpp文件代码如下：
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#include "SettingScene.h"
USING_NS_CC;
using namespace CocosDenshion;
… …
bool Setting::init()
{
if ( !Layer::init() )
{
return false;
}
log("Setting init");
Size visibleSize = Director::getInstance()->getVisibleSize();
Point origin = Director::getInstance()->getVisibleOrigin();
Sprite *bg = Sprite::create("setting-back.png");
bg->setPosition(Point(origin.x + visibleSize.width/2,
origin.y + visibleSize.height /2));
this->addChild(bg);
//音效
auto soundOnMenuItem = MenuItemImage::create(
"on.png",
"on.png");
auto soundOffMenuItem = MenuItemImage::create(
"off.png",
"off.png");
auto soundToggleMenuItem = MenuItemToggle::createWithCallback(
CC_CALLBACK_1(Setting::menuSoundToggleCallback, this),
soundOffMenuItem,
soundOnMenuItem,
NULL);
soundToggleMenuItem->setPosition(Director::getInstance()->convertToGL(Point(818, 220)));
//背景音乐
auto musicOnMenuItem = MenuItemImage::create(
"on.png",
"on.png");
auto musicOffMenuItem = MenuItemImage::create(
"off.png",
"off.png");
auto musicToggleMenuItem = MenuItemToggle::createWithCallback(
CC_CALLBACK_1(Setting::menuMusicToggleCallback, this),
musicOffMenuItem,
musicOnMenuItem,
NULL );
musicToggleMenuItem->setPosition(Director::getInstance()->convertToGL(Point(818, 362)));
//Ok按钮
auto okMenuItem = MenuItemImage::create(
"ok-down.png",
"ok-up.png",
CC_CALLBACK_1(Setting::menuOkCallback, this));
okMenuItem->setPosition(Director::getInstance()->convertToGL(Point(600, 510)));
Menu* mn = Menu::create(soundToggleMenuItem, musicToggleMenuItem,okMenuItem, NULL);
mn->setPosition(Point::ZERO);
this->addChild(mn);
return true;
}
void Setting::menuOkCallback(Ref* pSender)
{
Director::getInstance()->popScene();
if (isEffect) {
SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav"); ①
}
}
void Setting::menuSoundToggleCallback(Ref* pSender) ②
{
auto soundToggleMenuItem = (MenuItemToggle*)pSender;
log("soundToggleMenuItem %d", soundToggleMenuItem->getSelectedIndex());
if (isEffect) {
SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav"); ③
}
if (soundToggleMenuItem->getSelectedIndex() == 1) {//选中状态Off -> On ④
isEffect = false;
} else {
isEffect = true;
SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav"); ⑤
}
}
void Setting::menuMusicToggleCallback(Ref* pSender) ⑥
{
auto musicToggleMenuItem = (MenuItemToggle*)pSender;
log("musicToggleMenuItem %d", musicToggleMenuItem->getSelectedIndex());
if (musicToggleMenuItem->getSelectedIndex() == 1) {//选中状态Off -> On ⑦
SimpleAudioEngine::getInstance()->stopBackgroundMusic("sound/Synth.mp3");
} else {
SimpleAudioEngine::getInstance()->playBackgroundMusic("sound/Synth.mp3");
}
if (isEffect) {
SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav"); ⑧
}
}
void Setting::onEnter()
{
Layer::onEnter();
log("Setting onEnter");
}
void Setting::onEnterTransitionDidFinish()
{
Layer::onEnterTransitionDidFinish();
log("Setting onEnterTransitionDidFinish");
isEffect = true;
//播放
SimpleAudioEngine::getInstance()->playBackgroundMusic("sound/Synth.mp3", true); ⑨
}
void Setting::onExit()
{
Layer::onExit();
log("Setting onExit");
}
void Setting::onExitTransitionDidStart()
{
Layer::onExitTransitionDidStart();
log("Setting onExitTransitionDidStart");
}
void Setting::cleanup()
{
Layer::cleanup();
log("Setting cleanup");
//停止
SimpleAudioEngine::getInstance()->stopBackgroundMusic("sound/Synth.mp3"); ⑩
}
上述代码第①、③、⑧行是在判断isEffect为true（音效播放开关打开）情况下播放音效。
代码第②行menuSoundToggleCallback是用户点击音效开发按钮时候回调函数，其中第④行代码是判断是否按钮状态从Off -> On，如果是则将开关变量isEffect 设置为false，否则为true，而且通过第⑤行代码SimpleAudioEngine::getInstance()->playEffect("sound/Blip.wav")播放一次音效。
代码第⑥行menuMusicToggleCallback是用户点击背景音乐按钮时候回调函数，其中第⑦行代码是判断是否按钮状态从Off -> On，如果是则停止播放背景音乐，否则为开始播放。
第⑧行代码是onEnterTransitionDidFinish()函数中播放背景音乐。第⑨行代码是cleanup()函数中停止播放背景音乐。
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原文：http://my.oschina.net/u/1410370/blog/298339