[cocos2d-x]关于CC_CALLBACK

CC_CALLBACK的代码

// 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__)

CC_CALLBACK中的一些参数

_selector_：回调函数指针
_target_：执行这个回调函数的具体对象指针
std::placeholders::_1：占位符
_VA_ARGS_：可变长参数列表

CC_CALLBACK后面跟的数字表示回调函数所带有的参数个数

举例

    listner->onTouchBegan = CC_CALLBACK_2(GameTest::onTouchBegan,this);//带有两个占位符
    listner->onTouchMoved = CC_CALLBACK_2(GameTest::onTouchMoved, this);//带有两个占位符
    listner->onTouchEnded = CC_CALLBACK_2(GameTest::onTouchEnded, this);//带有两个占位符

库中的一些宏定义

typedef void (Ref::*SEL_CallFunc)();
typedef void (Ref::*SEL_CallFuncN)(Node*);
typedef void (Ref::*SEL_CallFuncND)(Node*, void*);
typedef void (Ref::*SEL_CallFuncO)(Ref*);
typedef void (Ref::*SEL_MenuHandler)(Ref*);
typedef void (Ref::*SEL_SCHEDULE)(float);

#define CC_CALLFUNC_SELECTOR(_SELECTOR) static_cast<cocos2d::SEL_CallFunc>(&_SELECTOR)
#define CC_CALLFUNCN_SELECTOR(_SELECTOR) static_cast<cocos2d::SEL_CallFuncN>(&_SELECTOR)
#define CC_CALLFUNCND_SELECTOR(_SELECTOR) static_cast<cocos2d::SEL_CallFuncND>(&_SELECTOR)
#define CC_CALLFUNCO_SELECTOR(_SELECTOR) static_cast<cocos2d::SEL_CallFuncO>(&_SELECTOR)
#define CC_MENU_SELECTOR(_SELECTOR) static_cast<cocos2d::SEL_MenuHandler>(&_SELECTOR)
#define CC_SCHEDULE_SELECTOR(_SELECTOR) static_cast<cocos2d::SEL_SCHEDULE>(&_SELECTOR)