工厂方法模式(Factory Method)

  工厂方法模式

定义了一个用于创建对象的接口，让子类决定实例化那一个类。工厂方法使一个类的实例化延迟到其子类。

UML图如下：

C++实现代码如下：

 /* Author: ACb0y Date: 2010年12月15日22:49:10 */ #include <iostream> using namespace std; class LeiFeng { public: virtual void Sweep() { cout << "扫地" << endl; } virtual void Wash() { cout << "洗衣" << endl; } virtual void BuyRice() { cout << "买米" << endl; } }; class Undergraduate : public LeiFeng { public: void Sweep() { cout << "大学生"; LeiFeng::Sweep(); } void Wash() { cout << "大学生"; LeiFeng::Wash(); } void BuyRice() { cout << "大学生"; LeiFeng::BuyRice(); } }; class Volunteer : public LeiFeng { public: void Sweep() { cout << "志愿者"; LeiFeng::Sweep(); } void Wash() { cout << "志愿者"; LeiFeng::Wash(); } void BuyRice() { cout << "志愿者"; LeiFeng::BuyRice(); } }; //工厂抽象类 class Factory { public: virtual LeiFeng * CreateLeiFeng() = 0; }; //具体的大学生工厂 class UndergraduateFactory : public Factory { public: LeiFeng * CreateLeiFeng() { return new Undergraduate(); } }; //具体的志愿者工厂 class VolunteerFactory : public Factory { public: LeiFeng * CreateLeiFeng() { return new Volunteer(); } }; int main() { Factory * p_factory = new UndergraduateFactory(); LeiFeng * p_student = p_factory->CreateLeiFeng(); p_student->Sweep(); p_student->Wash(); p_student->BuyRice(); delete p_factory; p_factory = NULL; p_factory = new VolunteerFactory(); delete p_student; p_student = NULL; p_student = p_factory->CreateLeiFeng(); p_student->Sweep(); p_student->Wash(); p_student->BuyRice(); delete p_factory; p_factory = NULL; delete p_student; p_student = NULL; return 0; }

运行结果如下：