c++命令模式

1.命令模式简介

   将一个请求封装为一个对象，从而使你可用不同的请求对客户进行参数化，对请求排队或记录请求日志。以及支持可撤销的操作。

2.源码实现

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

//烤肉师傅
class BarbecueMaster
{
public:
    void MakeMutton()
    {
        cout << "烤羊腿喽" << endl;
    }

    void MakeChiken()
    {
        cout << "烤鸡肉喽" << endl;
    }
};

//命令类
class Command
{
protected:
    BarbecueMaster *m_master;

public:
    Command(BarbecueMaster *p)
    {
        m_master = p;
    }

    virtual void executeCmd() = 0;
};

class CommandMutton : public Command
{
public:
    CommandMutton(BarbecueMaster *p) : Command(p) {};

    void executeCmd()
    {
        m_master->MakeMutton();
    }
};

class CommandChiken : public Command
{
public:
    CommandChiken(BarbecueMaster *p) : Command(p) {};

    void executeCmd()
    {
        m_master->MakeChiken();
    }
};

//服务员
class Waiter
{
private:
    vector<Command *> m_vec;

public:
    ~Waiter()
    {
        for(auto it=m_vec.begin(); it!=m_vec.end(); it++)
        {
            delete(*it);
        }

        m_vec.clear();
    }

    void add(Command *p)
    {
        m_vec.push_back(p);
    }

    void remove(Command *p)
    {
        for(auto it=m_vec.begin(); it!=m_vec.end(); it++)
        {
            if(*it == p)
            {
                delete(*it);
                break;
            }
        }
    }

    void submitCmd()
    {
        for(auto it=m_vec.begin(); it!=m_vec.end(); it++)
        {
            (*it)->executeCmd();
        }
    }
};

int main(int argc, char **argv)
{
    Waiter *pWaiter = new Waiter();
    BarbecueMaster *pBarbecueMaster = new BarbecueMaster();

    pWaiter->add(new CommandMutton(pBarbecueMaster));
    pWaiter->add(new CommandChiken(pBarbecueMaster));
    pWaiter->add(new CommandMutton(pBarbecueMaster));

    pWaiter->submitCmd();

    delete pBarbecueMaster;
    delete pWaiter;

    return 0;
}

3.编译源码

$ g++ -o example example.cpp

4.运行及其结果

$ ./example
烤羊腿喽
烤鸡肉喽
烤羊腿喽