[GoF設計模式]Proxy模式和Strategy模式的C++實現

  這個星期寫寫設計模式吧，一天兩到三個，今天起個頭兒。

  今天要寫的是代理模式(Proxy)和策略模式(Strategy),用C++做個簡單的例子實現。

  先不太規範了，一般的類就寫在一個頭文件中得了，連定義帶實現，以後回過頭來再看的時候，也能不麻煩點。呵呵。

  還有以後出現要用“Rule of Three”的地方，先不做過細考慮，主要是側重在模式本身。

  所有的程序均在GNU G++編譯器下調試通過。

 

1-[Proxy 模式]

圖解：

 

代碼：

/******************************************************************* * * DESCRIPTION: Subject Class Definition Of Proxy Pattern Gof * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #ifndef _H_SUBJECT #define _H_SUBJECT class Subject { public: /*Constructor and Destructor*/ Subject(){} virtual ~Subject(){} /*Concreate Method*/ /// <summary> /// A Pure Virtual Method -> Abstract Class /// </summary> /// <returns></returns> virtual void Request()=0; }; #endif 

 

/******************************************************************* * * DESCRIPTION:RealSubject Class inherited from Subject * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #ifndef _H_REALSUBJECT #define _H_REALSUBJECT /*Include Files*/ #include "Subject.h" class RealSubject:public Subject { /*Concreate Method*/ public: /*Constructor and Destructor*/ RealSubject(){} virtual ~RealSubject(){} /*Concreate Method*/ /// <summary> /// Implement the method of Request ,which inherited from Subject /// </summary> /// <returns>None</returns> virtual void Request() { std::cout<<"RealSubject::Request() be called!"<<std::endl; return; } }; #endif

 

/******************************************************************* * * DESCRIPTION: ProxySubject Class, inherited from Subject * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #ifndef _H_PROXYSUBJECT #define _H_PROXYSUBJECT /**Inlcude Files**/ #include "Subject.h" class ProxySubject:public Subject { public: /*Constructor and Destructor*/ ProxySubject(Subject *pSubject) { this->_subject=pSubject; } /// <summary> /// Caution, Delete the Memory /// </summary> /// <returns></returns> virtual ~ProxySubject() { delete _subject; } /*Concreate Method*/ /// <summary> /// Just Call the Real Request() Function /// </summary> /// <returns>None</returns> virtual void Request() { this->_subject->Request(); } private: Subject *_subject; }; #endif

 

/******************************************************************* * * DESCRIPTION: GOF-Proxy模式 * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ /*Include Files*/ #include <iostream> using namespace std; #include "Subject.h" #include "RealSubject.h" #include "ProxySubject.h" /// <summary> /// Just a Proxy Pattern Example /// </summary> /// <param name="argc"></param> /// <param name="argv"></param> /// <returns></returns> int main (int argc, char *argv[]) { /*GOF-Prototype Pattern*/ Subject* pSubject=new RealSubject(); /*New ProxySubject*/ ProxySubject *pProxySubject=new ProxySubject(pSubject);/*Parameter is IMP*/ /*Call its Request*/ cout<<"/n"<<endl; pProxySubject->Request(); return 0; }

 輸出：

 

 

 

2-[ Strategy 模式]

圖解：

 

 

代碼：

/******************************************************************* * * DESCRIPTION: MathOperation Class (Abstract Class) * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #ifndef MATHOPERATION_H_ #define MATHOPERATION_H_ class MathOperation { public: /*Constructor and Destructor*/ MathOperation(){} virtual ~MathOperation(){} /// <summary> /// Pure Virtual Method, Just interface /// </summary> /// <param name="left">left number</param> /// <param name="right">right number</param> /// <returns></returns> virtual float oper(float left,float right)=0; }; #endif

 

/******************************************************************* * * DESCRIPTION: AddOperation Class * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #ifndef ADDOPERATION_H_ #define ADDOPERATION_H_ /*Include Files*/ #include "MathOperation.h" class AddOperation:public MathOperation { public: /*Constructor and Destructor*/ AddOperation(){} virtual ~AddOperation(){} /// <summary> /// Addition Operation /// </summary> /// <param name="left">left number</param> /// <param name="right">right number</param> /// <returns></returns> virtual float oper(float left, float right) { return left+right; } }; #endif

 

/******************************************************************* * * DESCRIPTION: * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #ifndef SUBSTRACTOPERATION_H_ #define SUBSTRACTOPERATION_H_ #include "MathOperation.h" class SubstractOperation:public MathOperation { public: SubstractOperation(){} virtual ~SubstractOperation(){} /// <summary> /// Pure Virtual Method, Just interface /// </summary> /// <param name="left">left number</param> /// <param name="right">right number</param> /// <returns></returns> virtual float oper(float left, float right) { return left-right; } }; #endif

 

/******************************************************************* * * DESCRIPTION: * * AUTHOR: * * DATE:2009-9-15 * *******************************************************************/ #ifndef MULTIPLEOPERATION_H_ #define MULTIPLEOPERATION_H_ #include "MathOperation.h" class MultipleOperation:public MathOperation { public: /*Constructor and Destructor*/ MultipleOperation(){} virtual ~MultipleOperation(){} /*Concreate Method*/ /// <summary> /// Multiple Operation /// </summary> /// <param name="left">left number</param> /// <param name="right">right number</param> /// <returns></returns> virtual float oper(float left, float right) { return left*right; } }; #endif

 

/******************************************************************* * * DESCRIPTION: * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #ifndef DIVISIONOPERATION_H_ #define DIVISIONOPERATION_H_ /*Include Files*/ #include "MathOperation.h" #include <iostream> using namespace std; class DivisionOperation:public MathOperation { public: /*Constructor and Destructor*/ DivisionOperation(){} virtual ~DivisionOperation(){} /// <summary> /// Division Operation /// </summary> /// <param name="left">left number</param> /// <param name="right">right number</param> /// <returns></returns> virtual float oper(float left, float right) { /*when right is zero , result is 1.#INF ,it is infinite*/ return left/right; } }; #endif

 

/******************************************************************* * * DESCRIPTION: Calculator Class :call the MathOperation Class * * AUTHOR:Neesky * * DATE:2009-9-16 * *******************************************************************/ #ifndef CALCULATOR_H_ #define CALCULATOR_H_ /** include files **/ #include "MathOperation.h" class Calculator { public: /*Constructor and Destructor*/ Calculator(MathOperation* pMathOperation) { this->_mathOperation=pMathOperation; } /// <summary> /// Delete the memory applicated /// </summary> /// <returns></returns> virtual ~Calculator() { if(_mathOperation!=0) { delete this->_mathOperation; } } /*Concreate Method*/ /// <summary> /// Call the function of MathOperation /// </summary> /// <returns></returns> float DoCalculation(float left,float right) { return this->_mathOperation->oper(left,right); } private: MathOperation* _mathOperation; }; #endif

 

/******************************************************************* * * DESCRIPTION:GoF- Strategy Pattern [Strategy模式] * * AUTHOR:Neesky * * DATE:2009-9-15 * *******************************************************************/ #include "Calculator.h" #include "AddOperation.h" #include "SubstractOperation.h" #include "MultipleOperation.h" #include "DivisionOperation.h" #include "MathOperation.h" #include <iostream> using namespace std; int main (int argc, char *argv[]) { float left=0.1, right=0.3; float errRightZero=0.0; cout<<endl<<endl; MathOperation* mathOper = new AddOperation(); Calculator* cal=new Calculator(mathOper); cout<<"ADD: "<<left<<" + "<<right<<" = "<<cal->DoCalculation(left,right)<<endl<<endl; mathOper= new SubstractOperation(); cal=new Calculator(mathOper); cout<<"SUB: "<<left<<" - "<<right<<" = "<<cal->DoCalculation(left,right)<<endl<<endl; mathOper= new MultipleOperation(); cal=new Calculator(mathOper); cout<<"MUL: "<<left<<" x "<<right<<" = "<<cal->DoCalculation(left,right)<<endl<<endl; mathOper= new DivisionOperation(); cal=new Calculator(mathOper); cout<<"DIV: "<<left<<" / "<<right<<" = "<<cal->DoCalculation(left,right)<<endl<<endl; cout<<"DIV: "<<left<<" / "<<errRightZero<<" = "<<cal->DoCalculation(left,errRightZero)<<endl<<endl; /*Clear*/ if(cal!=0)delete cal; return(0); }

 

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