设计模式10——命令模式

命令模式中，命令抽象成一个借口，包含一个命令的执行者，能够派生出各种不同的命令。并有一个命令的管理者，能够添加各种命令，添加完后，在必要的时候通知执行者执行这些命令。

Command.h内容

#ifndef Command_H_H
#define Command_H_H

#include <iostream>
#include <vector>
using namespace std;


class Cooker
{
public:
    void makeIce() { cout << "Make a Ice!" << endl; }
    void makeJuice() { cout << "Make a Juice!" << endl; }
};

class Command
{
public:
    Command() : cooker(NULL) {}
    virtual void excute() = 0;
    virtual ~Command() {}
    void setCooker(Cooker *cooker0) { cooker = cooker0; }
protected:
    Cooker *cooker;
};

class CommandIce : public Command
{
public:
    virtual void excute() { cooker->makeIce();  }
};

class CommandJuice : public Command
{
public:
    virtual void excute() { cooker->makeJuice(); }
};

class Waiter
{
public:
    Waiter() : cooker(NULL) {}
    void addCommand(Command *command){
        command->setCooker(cooker);
        vecCommand.push_back(command);
    }
    void sendCommand(){
        for(size_t i=0; i<vecCommand.size(); ++i){
            vecCommand[i]->excute();
        }
    }
    void setCooker(Cooker *cooker0) { cooker = cooker0; }

private:
    vector<Command*> vecCommand;
    Cooker* cooker;
};



void CommandTest()
{
    Cooker *cooker = new Cooker();
    Waiter *waiter = new Waiter();
    waiter->setCooker(cooker);

    Command *command1 = new CommandIce();
    Command *command2 = new CommandJuice();
    waiter->addCommand(command1);
    waiter->addCommand(command2);

    waiter->sendCommand();
    delete waiter;
    delete cooker;
}

#endif

运行结果：

实例中，Waiter是命令的管理者，Cooker是命令执行者，添加makeIce和makeJuice两种命令并执行。