本篇的主題就是揭露CC_CALLBACK 與 std::bind之間不可告人的祕密......

首先看一段程式碼：

//先是建立3個精靈
boy = Sprite::create("boy.png");//建立boy
boy->setPosition(Point(visibleSize.width/2,visibleSize.height/2));
this->addChild(boy,1);

girl_1 = Sprite::create("girl_1.png");//建立girl1
girl_1->setPosition(Point(visibleSize.width/3,visibleSize.height/2));
girl_1->setTag(10);
this->addChild(girl_1,1);

girl_2 = Sprite::create("girl_3.png");//建立girl2
girl_2->setPosition(Point(2*visibleSize.width/3,visibleSize.height/2));
girl_2->setTag(20);
this->addChild(girl_2,1);

//讓boy運動，通過Callfunc回撥到callback1
boy->runAction(CCSequence::create(MoveBy::create(1.0f,Point(0,100)),
									CallFunc::create(CC_CALLBACK_0(HelloWorld::callback1,this)),
									NULL));
 

void HelloWorld::callback1()
{
	CCLOG("in callback1");
	//girl1運動，最後回撥到callback2
	girl_1->runAction(CCSequence::create(MoveBy::create(1.0f,Point(0,150)),
											CallFunc::create(CC_CALLBACK_0(HelloWorld::callback2,this,girl_1)),
											NULL));
}
void HelloWorld::callback2(Node* sender)
{
	//girl2運動，最後回撥到callback3
	girl_2->runAction(CCSequence::create(MoveBy::create(1.0f,Point(0,200)),
		CallFunc::create(CC_CALLBACK_0(HelloWorld::callback3,this,girl_2,99)),
		NULL));

	CCLOG("in callback2,sender tag is:%d",(Sprite*)sender->getTag());
}
void HelloWorld::callback3(Node* sender, long data)
{
	//最終輸出
	CCLOG("in callback3,everything is OK,sender tag is:%d,date is:%ld",(Sprite*)sender->getTag(),data);
	CCLOG("girl2 dandan ask:what fake the CC_CALLBACK is?");
}
 

整個過程就是boy“勾引”girl1，但girl1顯然對異性興趣不大，於是她也勾引girl2......可是，girl2對同性異性都沒興趣，她只是淡淡的說了句：CC_CALLBACK到底是什麼？，除錯如圖：

好吧，先讓我回口血，然後再來回答girl2的問題：CC_CALLBACK到底是什麼碗糕（東東）？
我們先進CC_CALLBACK原始碼裡看看：

// new callbacks based on C++11
#define CC_CALLBACK_0(__selector__,__target__, ...) std::bind(&__selector__,__target__, ##__VA_ARGS__)
#define CC_CALLBACK_1(__selector__,__target__, ...) std::bind(&__selector__,__target__, std::placeholders::_1, ##__VA_ARGS__)
#define CC_CALLBACK_2(__selector__,__target__, ...) std::bind(&__selector__,__target__, std::placeholders::_1, std::placeholders::_2, ##__VA_ARGS__)
#define CC_CALLBACK_3(__selector__,__target__, ...) std::bind(&__selector__,__target__, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3 ##__VA_ARGS__)
 

int callback(int one,char two,double three);

auto newCallback = bind(callback,_1,_2,1.5);
int x = newCallback(10,'h');  //這句相當於:int x = callback(10,'h',1.5);

std::placeholders::_1;

這樣編寫賊麻煩，所以在要使用_1時，可以加上這麼一句：
using namespace namespace_name; 恩，ok

恩，bind就介紹到這，講的比較淺，不理解的可以百度研究下。最後再回過頭來看下CC_CALLBACK的定義，是不是清晰多了？
最後在舉個例子吧，還是之前的boy,girl1,girl2，只是他們之間傳遞“愛意”的方式要換下了。不用CC_CALLBACK,改用std::bind。程式碼如下 ：

//讓boy運動，通過Callfunc回撥到callback1
boy->runAction(CCSequence::create(MoveBy::create(1.0f,Point(0,100)),
									CallFunc::create(std::bind(&HelloWorld::callback1,this)),
									NULL));

void HelloWorld::callback1()
{
	CCLOG("in callback1");
	//girl1運動，最後回撥到callback2
	girl_1->runAction(CCSequence::create(MoveBy::create(1.0f,Point(0,150)),
											CallFunc::create(std::bind(&HelloWorld::callback2,this,girl_1)),
											NULL));
	CCLOG("boy ask girl_1:can you do my girlFriends?");
}
void HelloWorld::callback2(Node* sender)
{
	//girl2運動，最後回撥到callback3
	girl_2->runAction(CCSequence::create(MoveBy::create(1.0f,Point(0,200)),
		CallFunc::create(std::bind(&HelloWorld::callback3,this,girl_1,99)),
		NULL));

	CCLOG("in callback2,sender tag is:%d",(Sprite*)sender->getTag());
	CCLOG("girl_1 ask girl_2:I love girl_2");
}
void HelloWorld::callback3(Node* sender, long data)
{
	//最終輸出
	CCLOG("in callback3,everything is OK,sender tag is:%d,date is:%ld",(Sprite*)sender->getTag(),data);
	CCLOG("girl2 dandan say:I know how to use CC_CALLBACK!");
}