设计模式之创建者模式

创建者(Builder)模式也属于构建型模式，其针对的情形是，一个东西是由多个部件构成的，并且需求的不同，各个构成部分也是有区别的，例如，汽车是有车体和轮子构成的，但是宝马车的车体和轮子与比亚迪的车体和轮子是不一样的，如下为创建者模式的C++实现，代码可到本人github网页下载：设计模式例子

/* * Example of `builder' design pattern. * Copyright (C) 2016 Leo Wang  * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */#include <iostream>using namespace std;class CPartA{public:    int m_quality; };class CPartB{public:    int m_quality; };class CProduct{public:    CPartA* cp_partA;    CPartB* cp_partB;public:    void Specification()    {        cout<<"This Product's quality:"<<endl;        cout<<"PartA's quality is !"<<cp_partA->m_quality<<endl;        cout<<"PartB's quality is !"<<cp_partB->m_quality<<endl;    };};class CBuilder{public:    virtual CPartA* BuildPartA()=0;    virtual CPartB* BuildPartB()=0;};class CGoodProductBuilder:public CBuilder{public:    CPartA* BuildPartA()    {        CPartA* cp_partA=new CPartA();        cp_partA->m_quality=100;        return cp_partA;    };    CPartB* BuildPartB()    {        CPartB* cp_partB=new CPartB();        cp_partB->m_quality=100;        return cp_partB;    };};class CBadProductBuilder:public CBuilder{public:    CPartA* BuildPartA()    {        CPartA* cp_partA=new CPartA();        cp_partA->m_quality=0;        return cp_partA;    };    CPartB* BuildPartB()    {        CPartB* cp_partB=new CPartB();        cp_partB->m_quality=0;        return cp_partB;    };};class CDirector{public:    CBuilder* cp_builder;public:    void SetBuilder(CBuilder* p_builder)    {        cp_builder=p_builder;    };    CProduct* GetProduct()    {        CProduct* cp_product=new CProduct();        cp_product->cp_partA=cp_builder->BuildPartA();        cp_product->cp_partB=cp_builder->BuildPartB();        return cp_product;    }};void main(){    CProduct* cp_product;    CDirector c_director;    CBuilder * cp_goodbuilder=new CGoodProductBuilder();    c_director.SetBuilder(cp_goodbuilder);    cp_product=c_director.GetProduct();    cp_product->Specification();    CBuilder* cp_badbuilder=new CBadProductBuilder();    c_director.SetBuilder(cp_badbuilder);    cp_product=c_director.GetProduct();    cp_product->Specification();};