#include <stdio.h>
#include <iostream>
using namespace std;
class LeiFeng {
    
public:
    void Sweep(){cout<<"sweep"<<endl;}
    void Wash(){cout<<"wash"<<endl;}
    void BuyRice(){cout<<"byerice"<<endl;}
    
};

class Undergraduate:public LeiFeng {
};

class Volunteer: public LeiFeng {
};

class SampleFactory {
public:
    static LeiFeng * CreateLeiFeng(int type)
    {
        LeiFeng * result = NULL;
        switch (type) {
            case 1:
                result = new Undergraduate();
                break;
                case 2:
                result = new Volunteer();
                break;
            default:
                break;
        }
        return  result;
    }
};


class IFactory {
    
public:
    virtual ~IFactory(){};
    virtual LeiFeng * CreateLeiFeng() = 0;
};

class UndergraduateFactory:public IFactory {
    
public:
    LeiFeng * CreateLeiFeng(){
        return new Undergraduate();
    }
};

class VolunteerFactory:public IFactory{
    
public:
    LeiFeng * CreateLeiFeng(){
        return new Volunteer();
    }
};

void testLesson5(){
    //sample factory
    LeiFeng * student1 = SampleFactory::CreateLeiFeng(graduate);
    LeiFeng * student2 = SampleFactory::CreateLeiFeng(graduate);
    LeiFeng * student3 = SampleFactory::CreateLeiFeng(graduate);
    student1->Wash();
    student2->Sweep();
    student3->Wash();
    
    IFactory * factory = new UndergraduateFactory();
    LeiFeng * student = factory->CreateLeiFeng();
    student->BuyRice();
    student->Sweep();
    student->Wash();

}

重要概念

簡單工廠模式的最大優(yōu)點在于工廠類中包含了必要的邏輯，根據(jù)客戶端的選擇條件動態(tài)實例化相關(guān)類，對客戶端來說，去處了對產(chǎn)品的依賴

工廠方法模式，定義了一個用于創(chuàng)建對象的接口，讓子類決定實例化哪一個類，工廠方法使一個類的實例化延遲到子類

好處就是能一次性改掉想改的東西，如果一個一個的去創(chuàng)建，那就比較蛋疼了