代码示例

产品及其子类实现

以手机加工厂开展例子

class Phone {
public:
    virtual void Operation() = 0; 
}
class Xiaomi : public Phone {
public:
       void Operation() override {
        printf("为发热而生！");
    }
}
class Huawei : public Phone {
public:
       void Operation() override {
        printf("不买不是中国人！");
    }
}
class Apple : public Phone {
public:
       void Operation() override {
        printf("傲视群雄！");
    }
}

工厂方法的不同实现

简单工厂（一般用于初期实现）

生成的逻辑一般位于工厂之中【if…else等】，不符合开放封闭原则

class PhoneFactory{
public:
    static Phone* createPhone(std::string Type){
        if(Type=="小米"){
            return new Xiaomi();
        }else if (Type == "华为"){
            return new Huawei();
        }else if (Type == "苹果"){
            return new Apple();
        }else{
            return NULL;
        }
    }
}

工厂方法（为每个产品子类创建一个子工厂）

符合开放封闭及单一职责

class PhoneFactory {
public:
    virtual ~PhoneFactory(){}
    virtual Product* FactoryMethod() const =0;
    void SomeOperation() const {
        Phone* phone=FactoryMethod();
        phone->Operation();
        delete product;
    }
}
/*Concrete Creator override factory method to supply different Product Class*/
class XiaomiFactory: public PhoneFactory{
public:
    Product* FactoryMethod() const override {
        return new Xiaomi();
    }
}
class HuaweiFactory: public PhoneFactory{
public:
    Product* FactoryMethod() const override {
        return new Huawei();
    }
}
class AppleFactory: public PhoneFactory{
public:
    Product* FactoryMethod() const override {
        return new Apple();
    }
}

抽象工厂（与上述两种方法无关）

主要整合多个不同的对象！

PC类

class PC{
public
    virtual void Operation() = 0 ;
}
class MiPC: public PC {
public:
    void Operation() override {
           printf("制造小米电脑"); 
    }    
}
class MAC: public PC {
public:
    void Operation() override {
           printf("制造苹果电脑"); 
    }    
}

抽象工厂

class MultiFactory{
public:
    Phone* phoneCreator() const =0 ;
    PC* pcCreator() const = 0;
}
class XiaomiFactory : public MultiFactory{
public:
    Phone* phoneCreator() const override {
        return new Xiaomi();
    }
    PC* pcCreator() const override {
        return new MiPC();
    }
}
class AppleFactory : public MultiFactory{
public:
    Phone* phoneCreator() const override {
        return new Apple();
    }
    PC* pcCreator() const override {
        return new MAC();
    }
}