c18-工厂方法例.txt

用什么语言能编制出好的程序

//在使用工厂方法模式

class Game
{
public:
	Maze();
	Maze * CreateMaze();

	//工厂方法集合
	virtual Maze * MakeMaze() const		{return new Maze;} 
	virtual Room * MakeRoom(int n) const    {return new Room(1);}
	virtual Wall * MakeWall() const 	{return new Wall;}
	virtual Door * MakeDoor(Room * r1,Room * r2) const
			{return new Door(r1,r2);} 	
private:
	Maze * theMaze;
	//...
};

Maze * Game::CreateMaze()
{
	Maze * aMaze=MakeMaze();
	Room * r1=MakeRoom(1);
	Room * r2=MakeRoom(2);
	Door * theDoor=MakeDoor(r1,r2);

	aMaze->AddRoom(r1);
	aMaze->AddRoom(r2);
	
	r1->SetSide(1,MakeWall());
	r1->SetSide(2,theDoor);
	r1->SetSide(3,MakeWall());
	r1->SetSide(4,MakeWall());

	r1->SetSide(1,MakeWall());
	r1->SetSide(2,MakeWall());
	r1->SetSide(3,MakeWall());
	r1->SetSide(4,theDoor);
	
	return aMaze;
}


//创建由Room类的子类RoomWithBomb等构成的迷宫游戏
class BombGame:public Game
{
public:
	BombGame();
	Room * MakeRoom(int n) const 	{return new RoomWithBomb(n);}
	Wall * MakeWall() const		{return new BombedWall;}
};