//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(shí)現(xiàn)很簡單，這里不做多余解釋?？梢钥吹剑纠a運(yùn)行后，p 的 Request 請(qǐng)求實(shí)際上是交給了 sub 來實(shí)際執(zhí)行。

再來看一個(gè)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(shí)現(xiàn)了邏輯和實(shí)現(xiàn)的徹底解耦。

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