C++实现26种设计模式——工厂模式

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原创最新推荐文章于 2026-07-27 10:13:35 发布 440 阅读 AI 写同款· GEO 优化 ›

C++创建型模式-工厂模式一、基础知识 1.1 简单工厂模式简单工厂模式（Simple Factory Pattern）专门定义一个类来负责创建其他类的实例，被创建的实例通常具有共同的父类。 1.2 简单工厂模式的角色二、C++实现工厂模式参考文献：【1】 ...... 阅读详情

C++实现26种设计模式之——工厂模式

谨以此系列文，纪念被设计模式整懵逼的那些年。
笔者没看过设计模式书，仅仅在工作中用过26种设计模式中的几种，其余大部分都是看demo代码。所以有错漏的地方，请各位兄弟批评指正。
而代码是年前大佬甩给我的，当时没时间细究，现在终于闲下来好好研究了，所以demo代码从哪儿下的笔者也不知（对那位写下的demo的老兄表示感谢和歉意，真心不是侵权）。
而学习间，笔者亦将demo代码改了许多，感谢开源，回馈开源，笔者接下来的代码也全部贴出，不用下载。

先看运行

以结果为导向，来看待问题，会清晰得多：
在这里插入图片描述
有三个厂，分别是：奔驰、宝马、奥迪；
于是，有三款产品，分别是：单车、汽车、摩托；
所以，工厂模式运用起来，大概应该是这样的效果：XX厂生产XX产品。

再来看main函数：

int main()
{
	// 奔驰
	AbstractFactory* pFactory = AbstractFactory::CreateFactory(FACTORY_TYPE::BENZ_FACTORY);
	ICarProduct *pCar = pFactory->CreateCar();
	IBikeProduct *pBike = pFactory->CreateBike();
	cout << pFactory->Name() << pCar->Name() << endl;
	cout << pFactory->Name() << pBike->Name() << endl;

	SAFE_DELETE(pCar);
	SAFE_DELETE(pBike);
	SAFE_DELETE(pFactory);
	
	// 宝马
	pFactory = AbstractFactory::CreateFactory(FACTORY_TYPE::BMW_FACTORY);
	IMotoBikeProduct* pMoto = pFactory->CreateMotoBike();
	pBike = pFactory->CreateBike();
	cout << pFactory->Name() << pMoto->Name() << endl;
	cout << pFactory->Name() << pBike->Name() << endl;

	SAFE_DELETE(pCar);
	SAFE_DELETE(pBike);
	SAFE_DELETE(pFactory);

	// 奥迪
	pFactory = AbstractFactory::CreateFactory(FACTORY_TYPE::AUDI_FACTORY);
	pMoto = pFactory->CreateMotoBike();
	pBike = pFactory->CreateBike();
	cout << pFactory->Name() << pMoto->Name() << endl;
	cout << pFactory->Name() << pBike->Name() << endl;

	SAFE_DELETE(pCar);
	SAFE_DELETE(pBike);
	SAFE_DELETE(pFactory);

	system("pause");
}

看着这样齐整的代码，咱再来想，要如何实现后面的类，才能实现后面的效果。
首先，很明显，AbstractFactory是个抽象工厂，CreateFactory也肯定是个静态函数，而这个函数就是通过FACTORY_TYPE这个枚举，来区分new出不同的工厂来的。
其次，不同的工厂，能创造出不同的产品（CreateCar()、CreateBike()、CreateMotoBike()），不用说肯定是多态，所以，工厂模式该怎么写，也大概能推断出来了。

源码（工厂类）

class AbstractFactory {
public:
	AbstractFactory() {}
	~AbstractFactory() {}
	virtual IBikeProduct* CreateBike() = 0;
	virtual IMotoBikeProduct* CreateMotoBike() = 0;
	virtual ICarProduct* CreateCar() = 0;

	static AbstractFactory* CreateFactory(FACTORY_TYPE type);

	string Name() { return m_name; }

protected:
	string m_name;
};


class BenChiFactory : public AbstractFactory {
public:
	BenChiFactory() { m_name = "奔驰"; }
	~BenChiFactory() {}

	IBikeProduct* CreateBike() { return new IBikeProduct; }
	IMotoBikeProduct* CreateMotoBike() { return new IMotoBikeProduct; }
	ICarProduct* CreateCar() { return new ICarProduct; }
};

class BaoMaFactory : public AbstractFactory {
public:
	BaoMaFactory() { m_name = "宝马"; }
	~BaoMaFactory() {}

	IBikeProduct* CreateBike() { return new IBikeProduct; }
	IMotoBikeProduct* CreateMotoBike() { return new IMotoBikeProduct; }
	ICarProduct* CreateCar() { return new ICarProduct; }

};

class AodiFactory : public AbstractFactory {
public:
	AodiFactory() { m_name = "奥迪"; }
	~AodiFactory() {}

	IBikeProduct* CreateBike() { return new IBikeProduct; }
	IMotoBikeProduct* CreateMotoBike() { return new IMotoBikeProduct; }
	ICarProduct* CreateCar() { return new ICarProduct; }

};

AbstractFactory* AbstractFactory::CreateFactory(FACTORY_TYPE type) {
	switch (type)
	{
	case BENZ_FACTORY:
	{
		return new BenChiFactory;
	}
	break;
	case BMW_FACTORY:
	{
		return new BaoMaFactory;
	}
	break;
	case AUDI_FACTORY:
	{
		return new AodiFactory;
	}
	break;
	default:
		break;
	}
}

源码（产品类）

class IProduct {
public:
	IProduct() {}
	~IProduct() {}
	string Name() { return m_name; }
protected:
	string m_name;
};

enum FACTORY_TYPE {
	BENZ_FACTORY = 0,
	BMW_FACTORY,
	AUDI_FACTORY
};

class IBikeProduct : public IProduct {
public:
	IBikeProduct() { m_name = "单车"; }
};

class IMotoBikeProduct : public IProduct {
public:
	IMotoBikeProduct() { m_name = "摩托"; }
};

class ICarProduct : public IProduct {
public:
	ICarProduct() { m_name = "汽车"; }

};

完整源码

#include "pch.h"
#include <iostream>
#include <string>

using namespace std;

#ifndef SAFE_DELETE(p) 
#define SAFE_DELETE(p){if(p){delete p; p = nullptr;}}
#endif

class IProduct {
public:
	IProduct() {}
	~IProduct() {}
	string Name() { return m_name; }
protected:
	string m_name;
};

enum FACTORY_TYPE {
	BENZ_FACTORY = 0,
	BMW_FACTORY,
	AUDI_FACTORY
};

class IBikeProduct : public IProduct {
public:
	IBikeProduct() { m_name = "单车"; }
};

class IMotoBikeProduct : public IProduct {
public:
	IMotoBikeProduct() { m_name = "摩托"; }
};

class ICarProduct : public IProduct {
public:
	ICarProduct() { m_name = "汽车"; }

};


class AbstractFactory {
public:
	AbstractFactory() {}
	~AbstractFactory() {}
	virtual IBikeProduct* CreateBike() = 0;
	virtual IMotoBikeProduct* CreateMotoBike() = 0;
	virtual ICarProduct* CreateCar() = 0;

	static AbstractFactory* CreateFactory(FACTORY_TYPE type);

	string Name() { return m_name; }

protected:
	string m_name;
};


class BenChiFactory : public AbstractFactory {
public:
	BenChiFactory() { m_name = "奔驰"; }
	~BenChiFactory() {}

	IBikeProduct* CreateBike() { return new IBikeProduct; }
	IMotoBikeProduct* CreateMotoBike() { return new IMotoBikeProduct; }
	ICarProduct* CreateCar() { return new ICarProduct; }
};

class BaoMaFactory : public AbstractFactory {
public:
	BaoMaFactory() { m_name = "宝马"; }
	~BaoMaFactory() {}

	IBikeProduct* CreateBike() { return new IBikeProduct; }
	IMotoBikeProduct* CreateMotoBike() { return new IMotoBikeProduct; }
	ICarProduct* CreateCar() { return new ICarProduct; }

};

class AodiFactory : public AbstractFactory {
public:
	AodiFactory() { m_name = "奥迪"; }
	~AodiFactory() {}

	IBikeProduct* CreateBike() { return new IBikeProduct; }
	IMotoBikeProduct* CreateMotoBike() { return new IMotoBikeProduct; }
	ICarProduct* CreateCar() { return new ICarProduct; }

};

AbstractFactory* AbstractFactory::CreateFactory(FACTORY_TYPE type) {
	switch (type)
	{
	case BENZ_FACTORY:
	{
		return new BenChiFactory;
	}
	break;
	case BMW_FACTORY:
	{
		return new BaoMaFactory;
	}
	break;
	case AUDI_FACTORY:
	{
		return new AodiFactory;
	}
	break;
	default:
		break;
	}
}


int main()
{
	// 奔驰
	AbstractFactory* pFactory = AbstractFactory::CreateFactory(FACTORY_TYPE::BENZ_FACTORY);
	ICarProduct *pCar = pFactory->CreateCar();
	IBikeProduct *pBike = pFactory->CreateBike();

	cout << pFactory->Name() << pCar->Name() << endl;
	cout << pFactory->Name() << pBike->Name() << endl;

	SAFE_DELETE(pCar);
	SAFE_DELETE(pBike);
	SAFE_DELETE(pFactory);

	// 宝马
	pFactory = AbstractFactory::CreateFactory(FACTORY_TYPE::BMW_FACTORY);
	IMotoBikeProduct* pMoto = pFactory->CreateMotoBike();
	pBike = pFactory->CreateBike();
	cout << pFactory->Name() << pMoto->Name() << endl;
	cout << pFactory->Name() << pBike->Name() << endl;

	SAFE_DELETE(pCar);
	SAFE_DELETE(pBike);
	SAFE_DELETE(pFactory);

	// 奥迪
	pFactory = AbstractFactory::CreateFactory(FACTORY_TYPE::AUDI_FACTORY);
	pMoto = pFactory->CreateMotoBike();
	pBike = pFactory->CreateBike();
	cout << pFactory->Name() << pMoto->Name() << endl;
	cout << pFactory->Name() << pBike->Name() << endl;

	SAFE_DELETE(pCar);
	SAFE_DELETE(pBike);
	SAFE_DELETE(pFactory);

	system("pause");
}

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