抽象工厂(Abstract Factory)模式看起来和前面看到的工厂方法很相似，只是它使用若干工厂方法(Factory Method）模式。每个工厂方法模式创建一个不同类型的对象。当创建一个工厂对象时，要决定将如何使用由那个工厂创建的所有对象。示例代码如下（假设要创建一个通用的游戏环境，并且希望它能支持不同类型的游戏）：
#include<iostream>
using namespace std;
class Obstacle
{
public:
virtual void action()=0;
};
class Player
{
public:
virtual void interactWith(Obstacle*)=0;
};
class Kitty: public Player
{
virtual void interactWith(Obstacle *ob)
{
cout<<"Kitty has encountered a";
ob->action();
}
};
class KungFuGuy: public Player
{
virtual void interactWith(Obstacle* ob)
{
cout<<"KungFuGuy now battles against a";
ob->action();
}
};
class Puzzle: public Obstacle
{
public:
void action(){cout<<"Puzzle"<<endl;}
};
class NastyWeapon: public Obstacle
{
public:
void action(){cout<<"NastyWeapon"<<endl;}
};
//the abstract factory
class GameElementFactory
{
public:
virtual Player* makePlayer()=0;
virtual Obstacle* makeObstacle()=0;
};
//concreate factories
class KittiesAndPuzzles:public GameElementFactory
{
public:
virtual Player* makePlayer(){return new Kitty;}
virtual Obstacle * makeObstacle(){return new Puzzle;}
};
class KillAndDismember:public GameElementFactory
{
public:
virtual Player* makePlayer(){return new KungFuGuy;}
virtual Obstacle *makeObstacle(){return new NastyWeapon;}
};
class GameEnvironment
{
GameElementFactory* gef;
Player* p;
Obstacle *ob;
public:
GameEnvironment(GameElementFactory * factory)
:gef(factory),p(factory->makePlayer()),ob(factory->makeObstacle()){}
void play(){p->interactWith(ob);}
~GameEnvironment()
{
delete p;
delete ob;
delete gef;
}
};
int main()
{
GameEnvironment
g1(new KittiesAndPuzzles),
g2(new KillAndDismember);
g1.play();
g2.play();
}
在此环境中，Player对象与Obstacle 对象交互，但是Player和Obstacle类型依赖于具体的游戏。可以选择特定的GameElementFactory来决定游戏的类型，然后GameEnvironment控制游戏的设置和进行。在本例中，游戏的设置和进行很简单，但是那些动作在很大程度上决定了游戏的结果。