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 .
 */
#include 
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:"<"PartA's quality is !"<m_quality<"PartB's quality is !"<m_quality<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();
};