【c++】用工厂模式实现计算器功能(附工厂模式代码)

约定不等于承诺〃 2022-07-12 17:50 182阅读 0赞

工厂模式

编译环境：Linux vim

DynBase.h

#ifndef _DYN_BASE_H_
    #define _DYN_BASE_H_
    
    #include <map>
    #include <string>
    using namespace std;
    
    typedef void* (*CREATE_FUNC)();
    
    class DynObjectFactory
    {
    public:
    	static void* CreateObject(const string& name)
    	{
    		map<string, CREATE_FUNC>::const_iterator it;
    		it = mapCls_.find(name);
    		if (it == mapCls_.end())
    			return 0;
    		else
    			return it->second();
    
    	}
    
    	static void Register(const string& name, CREATE_FUNC func)
    	{
    		mapCls_[name] = func;
    	}
    private:
    	static map<string, CREATE_FUNC> mapCls_;
    };
    
    // g++ 
    __attribute ((weak)) map<string, CREATE_FUNC> DynObjectFactory::mapCls_;
    
    class Register
    {
    public:
    	Register(const string& name, CREATE_FUNC func)
    	{
    		DynObjectFactory::Register(name, func);
    	}
    };
    
    #define REGISTER_CLASS(class_name) \
    class class_name##Register { \
    public: \
    	static void* NewInstance() \
    	{ \
    		return new class_name; \
    	} \
    private: \
    	static Register reg_; \
    }; \
    Register class_name##Register::reg_(#class_name, class_name##Register::NewInstance)
    
    
    #endif // _DYN_BASE_H_

Calculate.h

/*
    **************************************************************************
    * File Name: Calculate.cpp
    * Function : 1) 
    *            2) 
    * Author   : 
    * Created Time: 2017年02月16日 星期四 15时42分40秒
    **************************************************************************
    */
    
    #ifndef _CALCULATE_H_
    #define _CALCULATE_H_
    
    #include <string>
    
    using namespace std;
    
    class Cal
    {
    public:
        static double numA_;
        static double numB_;
    
        virtual void calOption() = 0;
        virtual ~Cal() {}
    };
    
    
    class Plus: public Cal
    {
    public:
        void calOption();
    //    ~Plus();
    };
    
    class Sub: public Cal
    {
    public:
        void calOption();
      //  ~Sub();
    };
    
    class Mul: public Cal
    {
    public:
        void calOption();
      //  ~Mul();
    };
    
    class Div: public Cal
    {
    public:
        void calOption();
      //  ~Div();
    };
    
    #endif

Calculate.cpp

/*
    **************************************************************************
    * File Name: Calculate.cpp
    * Function : 1) 
    *            2) 
    * Author   : 
    * Created Time: 2017年02月16日 星期四 15时53分14秒
    **************************************************************************
    */
    
    #include <iostream>
    #include <string>
    #include <string.h>
    #include <stdlib.h>
    #include "Calculate.h"
    #include "DynBase.h"
    //#include "DynObjectFactory.h"
    
    using namespace std;
    
    double Cal::numA_ = 0;
    double Cal::numB_ = 0;
    
    void Plus::calOption()
    {
        double result = Cal::numA_ + Cal::numB_;
    
        cout << Cal::numA_ << " + " << Cal::numB_ << " = " << result << endl;
    }
    
    void Sub::calOption()
    {
        double result = Cal::numA_ - Cal::numB_;
    
        cout << Cal::numA_ << " - " << Cal::numB_ << " = " << result << endl;
    }
    
    void Mul::calOption()
    {
        double result = Cal::numA_ * Cal::numB_;
    
        cout << Cal::numA_ << " x " << Cal::numB_ << " = " << result << endl;
    }
    
    void Div::calOption()
    {
        double result = Cal::numA_ / Cal::numB_;
    
        cout << Cal::numA_ << " / " << Cal::numB_ << " = " << result << endl;
    }
    
    REGISTER_CLASS(Plus);
    REGISTER_CLASS(Sub);
    REGISTER_CLASS(Mul);
    REGISTER_CLASS(Div);

Main.cpp

/*
    **************************************************************************
    * File Name: Main.cpp
    * Function : 1) 
    *            2) 
    * Author   : 
    * Created Time: 2017年02月16日 星期四 15时40分29秒
    **************************************************************************
    */
    
    #include <iostream>
    #include <string>
    #include <stdlib.h>
    #include <vector>
    #include "Calculate.h"
    //#include "DynObjectFactory.h"
    #include "DynBase.h"
    
    using namespace std;
    
    int main()
    {
        vector<Cal*> v;
        vector<Cal*>::const_iterator it;
    
        Cal* ps;
    
        string option;
    
        while(1)
        {
            system("clear");
            cout << "Calculator" << endl; 
            cout << "Please input a number:" << endl;
            cin >> Cal::numA_;
            cout << "Please input operation (Plus/Sub/Mul/Div)" << endl;
            cin >> option;
            cout << "Please input another number:" << endl;
            cin >> Cal::numB_;
            system("clear");
    
            ps = static_cast<Cal*>(DynObjectFactory::CreateObject(option));
            v.push_back(ps);
            it = v.begin();
            (*it)->calOption();
            delete(*it);
    
            cin.get();
            cin.get();
        }
    
        return 0;
    }