工厂方法模式【FACTORY METHOD PATTERN 】

factory.h

#ifndef _FACTORY_H_
#define _FACTORY_H_

class Human
{
public:
    virtual void laguage() = 0;
};


class WhiteHuman : public Human
{
public:
    void laguage();
};

class BlackHuman : public Human
{
public:
    void laguage();
};

class YellowHuman : public Human
{
public:
    void laguage();
};

class Factory
{
public:
    Factory()
    {
    }
    ~Factory()
    {
    }
public:
    static Human * getHum(Human * hu);
private:
    static Human * hum; /// < 不是静态的getHum不能直接调用；原因...
};

#endif

factory.c

#include "factory.h"
#include <iostream>
using namespace std;

void WhiteHuman::laguage()
{
    cout << "我说英语" << endl;
}

void BlackHuman::laguage()
{
    cout << "我说外语" << endl;
}

void YellowHuman::laguage()
{
    cout << "我说汉语" << endl;
}

Human * Factory::hum = NULL;

Human * Factory::getHum(Human * hu)
{
    if (NULL == hu)
        return NULL;
    hum = hu;

    return hum;
}

main.c

#include "factory.h"

int main(int argc, const char *argv[])
{
    Human * white = Factory::getHum(new WhiteHuman());
    white->laguage();
    delete white;

    Human * black = Factory::getHum(new BlackHuman());
    black->laguage();
    delete black;

    Human * yellow = Factory::getHum(new YellowHuman());
    yellow->laguage();
    delete yellow;

    return 0;
}