代理模式（Proxy）

#include "stdafx.h"
#include <iostream>
#include <memory>
using namespace std;

class Subject
{
public :
        virtual void Request() = 0;
};

class RealSubject :public Subject
{
public :
        virtual void Request()
       {
              cout << "真实的操作：RealSubject" << endl;
       }
};

class Proxy :public Subject
{
private :
        shared_ptr <RealSubject > _pRealSubject;
public :
        virtual void Request()
       {
               if (_pRealSubject == NULL)
                     _pRealSubject = shared_ptr <RealSubject >(new RealSubject );
              cout << "可以做一些内务处理！" << endl;
              _pRealSubject->Request();
       }

};

// ProxyMethod.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "Proxy.h"


int _tmain (int argc , _TCHAR * argv [])
{
        shared_ptr <Proxy > pProxy( new Proxy());
       pProxy->Request();

       getchar();
        return 0;
}