設計模式之建造者模式(Builder)

標籤：

建造者模式：

優點：

1.隔離了構建的步驟和具體的實現，為產品的具體實現提供了靈活性

2.封裝和抽象了每個步驟的實現，實現了依賴倒置原則

3.封裝了具體的步驟，減少了代碼冗餘

缺點：

1.要求構建的產品不能劇烈變化

程式碼範例：

Builer.h

#ifndef BULIDER_H#define BULIDER_Hclass Builder{public:    virtual void buildHead() = 0;    virtual void buildBody() = 0;    virtual void buildLeftArm() = 0;    virtual void buildRightArm() = 0;    virtual void buildLeftLeg() = 0;    virtual void buildRightLeg() = 0;};class ThinBuilder : public Builder{public:    void buildHead();    void buildBody();    void buildLeftArm();    void buildRightArm();    void buildLeftLeg();    void buildRightLeg();};class FatBuilder : public Builder{public:    void buildHead();    void buildBody();    void buildLeftArm();    void buildRightArm();    void buildLeftLeg();    void buildRightLeg();};class Director{public:    Director(Builder *builder);    void setBuilder(Builder *builder);    void creadte();private:    Builder *m_builder;};#endif // BULIDER_H

Builder.cpp

#include "bulider.h"#include <iostream>void ThinBuilder::buildHead(){    std::cout << "build thin Head" << std::endl;}void ThinBuilder::buildBody(){    std::cout << "build thin Body" << std::endl;}void ThinBuilder::buildLeftArm(){    std::cout << "build thin LeftArm" << std::endl;}void ThinBuilder::buildRightArm(){    std::cout << "build thin RightArm" << std::endl;}void ThinBuilder::buildLeftLeg(){    std::cout << "build thin LeftLeg" << std::endl;}void ThinBuilder::buildRightLeg(){    std::cout << "build thin RightLeg" << std::endl;}void FatBuilder::buildHead(){    std::cout << "build fat Head" << std::endl;}void FatBuilder::buildBody(){    std::cout << "build fat Body" << std::endl;}void FatBuilder::buildLeftArm(){    std::cout << "build fat LeftArm" << std::endl;}void FatBuilder::buildRightArm(){    std::cout << "build fat RightArm" << std::endl;}void FatBuilder::buildLeftLeg(){    std::cout << "build fat LeftLeg" << std::endl;}void FatBuilder::buildRightLeg(){    std::cout << "build fat RightLeg" << std::endl;}Director::Director(Builder *builder)    :m_builder(builder){}void Director::setBuilder(Builder *builder){    m_builder = builder;}void Director::creadte(){    m_builder->buildHead();    m_builder->buildBody();    m_builder->buildLeftArm();    m_builder->buildRightArm();    m_builder->buildLeftLeg();    m_builder->buildRightLeg();}

main.cpp

#include <iostream>#include "bulider.h"int main(){    FatBuilder fatBuilder;    Director director(&fatBuilder);    director.creadte();    std::cout << std::endl;    ThinBuilder thisBuilder;    director.setBuilder(&thisBuilder);    director.creadte();    return 0;}

設計模式之建造者模式(Builder)