Mediator 模式

在面向对象系统的设计和开发过程中，对象之间的交互和通信是最为常见的情况，因为对象间的交互本身就是一种通信。在系统比较小的时候，可能对象间的通信不是很多、对象也比较少，我们可以直接硬编码到各个对象的方法中。但是当系统规模变大，对象的量变引起系统复杂度的急剧增加，对象间的通信也变得越来越复杂，这时候我们就要提供一个专门处理对象间交互和通信的类，这个中介者就是 Mediator 模式

 1 //////////Colleage.h//////////////////////////////////////////////////////////////// 2 #pragma once 3 #include <string> 4 using namespace std; 5 class Mediator ; 6 class Colleage 7 { 8 public: 9     virtual ~Colleage();10     virtual void Action() = 0 ;11     virtual void SetState(const string& sdt) = 0 ;12     virtual string GetState() = 0 ;13 14 protected:15     Colleage();16     Colleage(Mediator* mdt);17     Mediator* _mdt ;18 19 private:20 };21 22 class ConcreteColleageA : public Colleage23 {24 public:25     ~ConcreteColleageA();26     ConcreteColleageA();27     ConcreteColleageA(Mediator* mdt);28     void Action();29     void SetState(const string& sdt);30     string GetState();31 32 protected:33 private:34     string _sdt ;35 };36 37 class ConcreteColleageB : public Colleage38 {39 public:40     ~ConcreteColleageB();41     ConcreteColleageB();42     ConcreteColleageB(Mediator* mdt);43     void Action();44     void SetState(const string& sdt);45     string GetState();46 47 protected:48 private:49     string _sdt ;50 };

 1 ///////////Mediator.h/////////////////////////////////////////////////////////////// 2 #pragma once 3 class Colleage; 4 class Mediator 5 { 6 public: 7     virtual ~Mediator(); 8     virtual void DoActionFromAtoB() = 0 ; 9     virtual void DoActionFromBtoA() = 0 ;10 protected:11     Mediator();12 private:13 };14 15 class ConcreteMediator : public Mediator16 {17 public:18     ~ConcreteMediator();19     ConcreteMediator();20     ConcreteMediator(Colleage* clgA ,Colleage* clgB);21 22     void SetColleageA( Colleage* clgA );23     void SetColleageB( Colleage* clgB );24 25     Colleage* GetColleageA();26     Colleage* GetColleageB();27 28     void IntroColleage(Colleage* clgA ,Colleage* clgB);29 30     void DoActionFromAtoB();31     void DoActionFromBtoA();32 protected:33 private:34     Colleage* _clgA ;35     Colleage* _clgB ;36 };

 1 ////////////Colleage.cpp////////////////////////////////////////////////////////////// 2 #include "Colleage.h" 3 #include "Mediator.h" 4 #include <string> 5 #include <iostream> 6 using namespace std; 7 Colleage::~Colleage() 8 { 9 10 }11 Colleage::Colleage()12 {13 14 }15 Colleage::Colleage(Mediator* mdt)16 {17     this->_mdt = mdt ;18 }19 20 ConcreteColleageA::~ConcreteColleageA()21 {22 23 }24 ConcreteColleageA::ConcreteColleageA()25 {26 27 }28 ConcreteColleageA::ConcreteColleageA(Mediator* mdt):Colleage(mdt)29 {30 31 }32 void ConcreteColleageA::SetState(const string& sdt)33 {34     this->_sdt = sdt ;35 }36 string ConcreteColleageA::GetState()37 {38     return _sdt ;39 }40 41 void ConcreteColleageA::Action()42 {43     this->_mdt->DoActionFromAtoB();44     cout<<"把消息："<<this->GetState()<<"传给B"<<endl;45 }46 47 ConcreteColleageB::~ConcreteColleageB()48 {49 50 }51 ConcreteColleageB::ConcreteColleageB()52 {53 54 }55 ConcreteColleageB::ConcreteColleageB(Mediator* mdt):Colleage(mdt)56 {57 58 }59 void ConcreteColleageB::SetState(const string& sdt)60 {61     this->_sdt = sdt ;62 }63 string ConcreteColleageB::GetState()64 {65     return _sdt ;66 }67 68 void ConcreteColleageB::Action()69 {70     this->_mdt->DoActionFromBtoA();71     cout<<"把消息："<<this->GetState()<<"传给A"<<endl;72 }

 1 //////////Mediator.cpp//////////////////////////////////////////////////////////////// 2 #include "Mediator.h" 3 #include "Colleage.h" 4 Mediator::Mediator() 5 { 6  7 } 8 Mediator::~Mediator() 9 {10 11 }12 13 ConcreteMediator::ConcreteMediator()14 {15 16 }17 ConcreteMediator::~ConcreteMediator()18 {19 20 }21 ConcreteMediator::ConcreteMediator(Colleage* clgA ,Colleage* clgB)22 {23     _clgA = clgA ;24     _clgB = clgB ;25 }26 void ConcreteMediator::DoActionFromAtoB()27 {28     _clgB->SetState(_clgA->GetState());29 }30 void ConcreteMediator::DoActionFromBtoA()31 {32     _clgA->SetState(_clgB->GetState());33 }34 35 void ConcreteMediator::SetColleageA( Colleage* clgA )36 {37     _clgA = clgA ;38 }39 void ConcreteMediator::SetColleageB( Colleage* clgB )40 {41     _clgB = clgB ;42 }43 Colleage* ConcreteMediator::GetColleageA()44 {45     return _clgA ;46 }47 Colleage* ConcreteMediator::GetColleageB()48 {49     return _clgB ;50 }51 52 void ConcreteMediator::IntroColleage(Colleage* clgA ,Colleage* clgB)53 {54     _clgA = clgA ;55     _clgB = clgB ;56 }

 1 //////main.cpp//////////////////////////////////////////////////////////////////// 2 #include "Colleage.h" 3 #include "Mediator.h" 4 #include <iostream> 5 using namespace std; 6 int main() 7 { 8     ConcreteMediator* m = new ConcreteMediator(); 9     Colleage* c1 = new ConcreteColleageA(m);10     Colleage* c2 = new ConcreteColleageB(m);11 12     m->IntroColleage(c1, c2);13     c1->SetState("你好！");14     c2->SetState("你是谁");15 16     cout<<c1->GetState()<<endl;17     cout<<c2->GetState()<<endl;18 19     c1->Action();20 21     cout<<c2->GetState()<<endl;22     getchar();23     return 0 ;24 25 }