只上图和代码吧
[cpp]
#include "stdafx.h"
#include <windows.h>
enum EOperator
{
ADD_OPER,
SUB_OPER
};
class MathOperator
{
public:
MathOperator(){;}
virtual ~MathOperator(){;}
void SetMember(int first, int second)
{
m_nFirst = first;
m_nSecond = second;
}
virtual int GetResult() = 0;
protected:
int m_nFirst;
int m_nSecond;
};
class AddOperator:public MathOperator
{
public:
int GetResult()
{
return m_nFirst + m_nSecond;
}
};
class SubOperator:public MathOperator
{
public:
int GetResult()
{
return m_nFirst - m_nSecond;
}
};
class OperatorFactory
{
public:
MathOperator *CreateOperator(EOperator eOper)
{
MathOperator *pOper = NULL;
switch (eOper)
{
case ADD_OPER:
pOper = new AddOperator();
break;
case SUB_OPER:
pOper = new SubOperator();
break;
}
return pOper;
}
};
int _tmain(int argc, _TCHAR* argv[])
{
OperatorFactory OFactrory;
MathOperator *pOper = OFactrory.CreateOperator(ADD_OPER);
pOper->SetMember(2, 3);
int nResult = pOper->GetResult();
if (pOper)
{
delete pOper;
pOper = NULL;
}
return 0;
}