代理模式典型的結(jié)構(gòu)圖為：
實際上，代理模式的想法非常簡單。
代理模式的實現(xiàn)：
完整代碼示例（code）：代理模式的實現(xiàn)很簡單，這里為了方便初學者的學習和參考，將給出完整的實現(xiàn)代碼（所有代碼采用 C++實現(xiàn)，并在 VC 6.0 下測試運行）。
代碼片斷 1：Proxy.h
//Proxy.h#ifndef _PROXY_H_#define _PROXY_H_class Subject{ public: virtual ~Subject(); virtual void Request() = 0; protected: Subject(); private:};class ConcreteSubject:public Subject{ public: ConcreteSubject(); ~ConcreteSubject(); void Request(); protected: private:};class Proxy{ public: Proxy(); Proxy(Subject* sub); ~Proxy(); void Request(); protected: private: Subject* _sub;};#endif //~_PROXY_H_ 代碼片斷 2：Proxy.cpp
//Proxy.cpp#include "Proxy.h"#include <iostream>using namespace std;Subject::Subject(){}Subject::~Subject(){}ConcreteSubject::ConcreteSubject(){}ConcreteSubject::~ConcreteSubject(){}void ConcreteSubject::Request(){ cout<<"ConcreteSubject......request ...."<<endl;}Proxy::Proxy(){}Proxy::Proxy(Subject* sub){ _sub = sub;}Proxy::~Proxy(){ delete _sub;}void Proxy::Request(){ cout<<"Proxy request...."<<endl; _sub->Request();} 代碼片斷 3：main.cpp
//main.cpp#include "Proxy.h"#include <iostream>using namespace std;int main(int argc,char* argv[]){ Subject* sub = new ConcreteSubject(); Proxy* p = new Proxy(sub); p->Request(); return 0;} 代碼說明：代理模式的實現(xiàn)很簡單，這里不做多余解釋。可以看到，示例代碼運行后，p 的 Request 請求實際上是交給了 sub 來實際執(zhí)行。
再來看一個例子：
#include <iostream> #include <string> using namespace std; class Receiver { private: string name; public: Receiver(string name):name(name) { } string GetName() { return name; } }; class Subject { public: virtual void display(){} }; class Sender:public Subject { Receiver *someone; public: void SetReceiver(Receiver *someone) { this->someone = someone; } virtual void display() { cout<<"i hate you:" << someone->GetName()<<endl; } }; class Proxy:public Subject { public: Subject *realobject; void SetClient(Subject *client) { this->realobject = client; } void display() { realobject->display(); } }; int main() { Receiver *recv = new Receiver("nobody"); Sender *obj = new Sender; obj->SetReceiver(recv); Proxy *proxy = new Proxy; proxy->SetClient(obj); proxy->display(); system("pause"); return 0; } 由此可見，代理模式最大的好處就是實現(xiàn)了邏輯和實現(xiàn)的徹底解耦。
