[结构型模式] 代理模式的理解

阳光穿透心脏的1/2处 2022-04-11 05:30 195阅读 0赞

\[img\]http://chuantu.biz/t5/5/1464940955x3738746553.jpg\[/img\]  
\[img\]http://chuantu.biz/t5/5/1464940981x3738746553.jpg\[/img\]  
\[color=red\]\[b\]头文件\[/b\]\[/color\]

//ProxyPattern.h
    
    #ifndef PROXY_PATTERN_H
    #define PROXY_PATTERN_H
    
    #include <Windows.h>
    #include <iostream>
    using namespace std;
    
    namespace ProxyPattern
    {
       
    #define SAFE_DELETE(p) if (p) { delete p; p = NULL;}
    
        //
        class CSubject
        {
       
        public:
            CSubject();
            virtual ~CSubject();
    
            virtual void Request() = 0;
        };
    
        //
        class CRealSubject : public CSubject
        {
       
        public:
            CRealSubject();
            virtual ~CRealSubject();
    
            virtual void Request();
        };
    
        //
        class CProxy : public CSubject
        {
       
        public:
            CProxy();
            virtual ~CProxy();
    
            virtual void Request();
    
        private:
            CRealSubject* m_pRealSubject;
        };
    
        //
        void ProxyPattern_Test();
    }
    
    #endif

\[color=red\]\[b\]实现\[/b\]\[/color\]

#include "ProxyPattern.h"
    
    namespace ProxyPattern
    {
       
        //
        CSubject::CSubject()
        {}
    
        CSubject::~CSubject()
        {}
    
        void CSubject::Request()
        {}
    
        //
        CRealSubject::CRealSubject(){}
        CRealSubject::~CRealSubject(){}
    
        void CRealSubject::Request()
        {
       
            cout<<"CRealSubject Request"<<endl;
        }
    
        //
        CProxy::CProxy()
            : m_pRealSubject(NULL)
        {}
    
        CProxy::~CProxy()
        {
       
            SAFE_DELETE(m_pRealSubject);
        }
    
        void CProxy::Request()
        {
       
            if (NULL == m_pRealSubject)
            {
       
                m_pRealSubject = new CRealSubject();
            }
            cout<<"CProxy Request"<<endl;
            m_pRealSubject->Request();
        }
    
        ///
        void ProxyPattern_Test()
        {
       
            CSubject *pSubject = new CProxy();
            pSubject->Request();
            SAFE_DELETE(pSubject);
        }
    }

\[color=red\]\[b\]客户端\[/b\]\[/color\]

#include "ProxyPattern.h"
    
    
    #include <iostream>
    using namespace std;
    using namespace ProxyPattern;
    
    void main()
    {
       
        ProxyPattern_Test();
    }

\[color=red\]\[b\]运行结果\[/b\]\[/color\]  
\[img\]http://chuantu.biz/t5/5/1464941002x3738746553.jpg\[/img\]