C++工厂方法模式

 

class IFactoryBase
{
public:
    IFactoryBase(void);
    virtual ~IFactoryBase(void);

public:
    virtual IProductBase* CreateProduct() = 0;
};

class IProductBase
{
public:
    IProductBase(void);
    ~IProductBase(void);

public:
    virtual void SetProductInfo() = 0;
};

class CFactoryA : public IFactoryBase
{
public:
    CFactoryA(void);
    ~CFactoryA(void);

public:
    virtual IProductBase* CreateProduct(); 
};

IProductBase* CFactoryA::CreateProduct()
{
    return new CProductA();
}

class CProductA : public IProductBase
{
public:
    CProductA(void);
    ~CProductA(void);

public:
    void SetProductInfo(){}
};

class CFactoryB : public IFactoryBase
{
public:
    CFactoryB(void);
    ~CFactoryB(void);

public:
    virtual IProductBase* CreateProduct();
};

IProductBase* CFactoryB::CreateProduct()
{
    return new CProductB();
}

class CProductB : public IProductBase
{
public:
    CProductB(void);
    ~CProductB(void);

public:
    virtual void SetProductInfo(){}
};

int _tmain(int argc, _TCHAR* argv[])
{
73     IFactoryBase *pFactory = new CFactoryA();
74     if (NULL != pFactory)
75     {
76         IProductBase *pProductBase = pFactory->CreateProduct();
77         if (NULL != pProductBase)
78         {
79             pProductBase->SetProductInfo();
80         }
81 
82         delete pProductBase;
83     }
84 
85     delete pFactory;

    return 0;
}

 

 

核心思想：将工厂抽象出来，将产品抽象出来，子工厂负责new 子产品指针，返回抽象产品类指针，外面调用时只需要生成基类工厂指针，调用创建产品函数，就可以对该产品进行具体的操作，优点是能够将添加产品完全独立出来不再修改内部代码。

与简单工厂比较：修正了简单工厂模式中不遵循开放---封闭原则，例如添加新产品时仍需要修改工厂基类内容，工厂方法模式将判断移动到客户端实现。

部分代码：