一般情況：
void showMsg(float)
{
cout << "show msg normal" << endl;
}
void (*p)(float);
然後這樣調用：
p = showMsg;
p(1.1f);
如果用於函數傳遞參數，這樣就不是很方便使用了，於是有了下面這種：
typedef void (*p1)(float);
p1 p1my = showMsg;
p1my(1.0f);
上面是一般的情況，那麼如何指向類成員的成員函數呢？
看下：
class Student
{
public:
void showMsg(float);
};
void Student::showMsg(float)
{
cout << "show msg in the Student Class" << endl;
}
typedef void (Student::*ps)(float);
使用如下：
Student s;
ps pstudent = &Student::showMsg;
(s.*pstudent)(2.0f);
好了，我們已經知道了，函數指針的簡單使用，那麼我大概模仿下cocos2dx3.2裏面的SEL_SCHEDULE的使用：
首先，定義Node節點，這個我隨便寫的
class Node
{
public:
static Node* create();
void autorelease();
protected:
Node();
virtual bool init();
virtual ~Node();
};
void Node::autorelease()
{
delete this;
}
Node* Node::create()
{
auto sp = new Node();
if(sp && sp->init())
{
}
else
{
delete sp;
}
return sp;
}
Node::Node()
{
}
Node::~Node()
{
cout << "the Node is destructed" << endl;
}
bool Node::init()
{
return true;
}
typedef void (Node::*SEL_SCHEDULE)(float);
#define schedule_selector(_SELECTOR) static_cast<SEL_SCHEDULE>(&_SELECTOR)
class Player : public Node
{
public:
static Player* create();
void show(float dt);
protected:
Player();
virtual ~Player();
virtual bool init();
};
void Player::show(float dt)
{
cout << "player show class" << endl;
}
Player::Player()
{
}
Player::~Player()
{
cout << "the player is destructed" << endl;
}
Player* Player::create()
{
auto sp = new Player();
if(sp && sp->init())
{
}
else
{
delete sp;
}
return sp;
}
bool Player::init()
{
SEL_SCHEDULE sel = schedule_selector(Player::show);
(this->*sel)(3.0f);
return true;
}
int main()
{
auto sp = Player::create();
SEL_SCHEDULE sel = schedule_selector(Player::show);
// SEL_SCHEDULE sel = static_cast<SEL_SCHEDULE>(&Player::show); //這種方式也是可以的
(sp->*sel)(2.2);
sp->autorelease();
return 0;
}
哎，上面這種是再外面使用，但是cocos2dx3.2是再裏面調用的，其實使用也是蠻簡單的，看下：
比如我要再Player::init函數中調用:
bool Player::init()
{
SEL_SCHEDULE sel = schedule_selector(Player::show);
(this->*sel)(3.0f);
return true;
}
好了到此結束吧.