1.意图
将抽象部分与它的实现部分分离，使它们都可以独立地变化。
2.动机
在抽象类与它的实现之间起到桥梁作用，使它们可以独立地变化。
3.适用性
4.结构
5.代码实例
#include <memory>
class AbstactionImpl;
class Abstration
{
public:
void virtual Operaion()=0;
void virtual SetImpl(std::shared_ptr<AbstactionImpl>& pImpl)=0;
protected:
std::shared_ptr<AbstactionImpl> m_pImpl;
};
class RedefinedAbstration : public Abstration
{
public:
void Operaion();
void SetImpl(std::shared_ptr<AbstactionImpl>& pImpl);
};
class AbstactionImpl
{
public:
void virtual OperationImpl()=0;
};
class ConcreteImplentorA : public AbstactionImpl
{
public:
void OperationImpl();
};
class ConcreteImplentorB : public AbstactionImpl
{
public:
void OperationImpl();
};
#include "Abstration.h"
#include "Implentor.h"
void RedefinedAbstration::Operaion()
{
m_pImpl->OperationImpl();
}
void RedefinedAbstration::SetImpl(std::shared_ptr<AbstactionImpl>& pImpl)
{
m_pImpl = pImpl;
}
#include <iostream>
#include "Implentor.h"
void ConcreteImplentorA::OperationImpl()
{
std::cout<<"ConcreteImplenorA Exectued" <<std::endl;
}
void ConcreteImplentorB::OperationImpl()
{
std::cout<<"ConcreteImplentorB Exectued"<<std::endl;
}
#include <memory>
#include "Abstration.h"
#include "Implentor.h"
int main()
{
std::shared_ptr<AbstactionImpl> pConcreteImplA(new ConcreteImplentorA);
std::shared_ptr<AbstactionImpl> pConcreteImplB(new ConcreteImplentorB);
std::shared_ptr<RedefinedAbstration> pRedefinedAbstration(new RedefinedAbstration);
pRedefinedAbstration->SetImpl(pConcreteImplA);
pRedefinedAbstration->Operaion();
pRedefinedAbstration->SetImpl(pConcreteImplB);
pRedefinedAbstration->Operaion();
while(1);
}
6.测试结果
7.效果
原文：http://www.cnblogs.com/zhengxingpeng/p/6686304.html