设计模式之工厂方法

工厂方法有点：
       修正了简单工厂模式中不遵守开放-封闭原则。工厂方法模式把选择判断移到了客户端去实现,如果想添加新功能就不用修改原来的类,直接修改客户端即可。

下面是代码：
#include
#include

using namespace std;

//实例基类，相当于Product(为了方便没有抽象)
class LeiFeng
{
public:
    virtual void Sweep()
    {
    cout << "雷锋扫地" << endl;
    }
};

//学雷锋的大学生，相当于ConcreteProduct
class Student : public LeiFeng
{
public:
    virtual void Sweep()
    {
    cout << "大学生扫地" << endl;
    }
};

//学雷锋的志愿者，相当于ConcreteProduct
class Volenter : public LeiFeng
{
public:
    virtual void Sweep()
    {
    cout << "志愿者扫地" << endl;
    }
};

//工厂基类Creator
class LeiFengFactory
{
public:
    virtual LeiFeng* CreateLeiFeng()
    {
    return new LeiFeng();
    }
};

//工厂具体类
class StudentFactory : public LeiFengFactory
{
public:
    virtual LeiFeng* CreateLeiFeng()
    {
    return new Student();
    }
};

class VolenterFactory: public LeiFengFactory
{
public:
    virtual LeiFeng* CreateLeiFeng()
    {
    return new Volenter();
    }
};

//客户端
int main()
{
    LeiFengFactory* lf = new LeiFengFactory();
    LeiFeng* s = lf->CreateLeiFeng();
    s->Sweep();
    delete s;
    delete lf;
   
    lf = new StudentFactory();
    s = lf->CreateLeiFeng();
    s->Sweep();
    delete s;
    delete lf;
   
    lf = new VolenterFactory();
    s = lf->CreateLeiFeng();
    s->Sweep();
    delete s;
    delete lf;
   
    return 0;
}