设计模式学习笔记（一）：简单工厂

《大话设计模式》学习笔记，参考链接 伍迷的小菜编程成长记

//operation.h
#pragma once

//操作类
class Operation
{
public:
    Operation(void);
    ~Operation(void);
    int GetNumberA(void) {return this->m_bNumberA;}
    int GetNumberB(void) {return this->m_bNumberB;}
    void SetNumberA(int numberA) {this->m_bNumberA = numberA;}
    void SetNumberB(int numberB) {this->m_bNumberB = numberB;}
    virtual int GetResult(void) = 0;

private:
    int m_bNumberA;
    int m_bNumberB;
};

//operation.cpp
#include "operation.h"

Operation::Operation(void)
{
}

Operation::~Operation(void)
{
}

//concreteoperation.h
#pragma once

#include "operation.h"

//加法操作
class OperationAdd : public Operation
{
public:
    OperationAdd(void);
    ~OperationAdd(void);
    int GetResult(void);
};

//减法操作
class OperationSub : public Operation
{
public:
    OperationSub(void);
    ~OperationSub(void);
    int GetResult(void);
};

//乘法操作
class OperationMul : public Operation
{
public:
    OperationMul(void);
    ~OperationMul(void);
    int GetResult(void);
};

//除法操作
class OperationDiv : public Operation
{
public:
    OperationDiv(void);
    ~OperationDiv(void);
    int GetResult(void);
};

//concreteoperation.cpp
#include "concreteoperation.h"

OperationAdd::OperationAdd(void)
{
}

OperationAdd::~OperationAdd(void)
{
}

int OperationAdd::GetResult(void)
{
    int result = 0;
    result = this->GetNumberA() + this->GetNumberB();
    return result;
}

OperationSub::OperationSub(void)
{
}

OperationSub::~OperationSub(void)
{
}

int OperationSub::GetResult(void)
{
    int result = 0;
    result = this->GetNumberA() - this->GetNumberB();
    return result;
}

OperationMul::OperationMul(void)
{
}

OperationMul::~OperationMul(void)
{
}

int OperationMul::GetResult(void)
{
    int result = 0;
    result = this->GetNumberA() * this->GetNumberB();
    return result;
}

OperationDiv::OperationDiv(void)
{
}

OperationDiv::~OperationDiv(void)
{
}

int OperationDiv::GetResult(void)
{
    int result = 0;
    result = this->GetNumberA() / this->GetNumberB();
    return result;
}

//operationfactory.h
#pragma once

#include "operation.h"
#include "concreteoperation.h"

//操作工厂
class OperationFactory
{
public:
    OperationFactory(void);
    ~OperationFactory(void);
    Operation* CreateOperation(int operationIndex); 
};

//operationfactory.cpp
#include <iostream>
#include "operationfactory.h"

using namespace std;

OperationFactory::OperationFactory(void)
{
}

OperationFactory::~OperationFactory(void)
{
}

Operation* OperationFactory::CreateOperation(int operationIndex)
{
    Operation *pOperation;
    switch(operationIndex)
    {
    case 1:
        pOperation = new OperationAdd();
        break;
    case 2:
        pOperation = new OperationSub();
        break;
    case 3:
        pOperation = new OperationMul();
        break;
    case 4:
        pOperation = new OperationDiv();
        break;
    }
    return pOperation;
}

//main.cpp
#include <iostream>
#include "operationfactory.h"

using namespace std;

int main(void)
{
    int numberA,numberB,result;
    int operationIndex;

    cout << "请输入数字A:" << endl;
    cin >> numberA;
    cout << endl << "请输入数字B:" << endl;
    cin >> numberB;
    cout << endl << "请选择运算类型:"
              << "(1)加法运算" << endl
              << "(2)减法运算" << endl
              << "(3)乘法运算" << endl
              << "(4)除法运算" << endl << endl;
    cin >> operationIndex;

    OperationFactory aOperationFactory;
    Operation *pOperation;
    pOperation = aOperationFactory.CreateOperation(operationIndex);
    
    pOperation->SetNumberA(numberA);
    pOperation->SetNumberB(numberB);
    result = pOperation->GetResult();
    cout << endl << "运算结果：" << result << endl << endl;

    delete pOperation;
    return 0;
}

(没有考虑各种输入异常)