笔记：回调函数小程序

#include <stdio.h>

typedef int(*pMyFun)(int a, int b);

static int myAdd(int a, int b)
{
return a + b;
}

static int mySub(int a, int b)
{
return a - b;
}

class myTest
{
public:
myTest();

~myTest();

public:
void setCallBack(pMyFun cb);
void start();
private:
pMyFun callback;
};

myTest::myTest()
{
callback = NULL;
}

myTest::~myTest()
{
}

void myTest::setCallBack(pMyFun cb)
{
callback = cb;
}

void myTest::start()
{
int a = 3, b = 7;
if(NULL != callback)
printf("ret of callback = %d\n", callback(a, b));
}

int main(int argc, char* argv[])
{
myTest test;
test.setCallBack(myAdd);
test.start();

test.setCallBack(mySub);
test.start();
}