设计模式：命令模式

命令模式：将一个请求封装一个对象，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，以及支持课撤销的操作

一个例子：烧烤厨师，各户的要求，服务员

 

代码如下：

//烧烤厨师

#ifndef BARBECUER_H#define BARBECUER_H#include <iostream>using std::cout;using std::endl;class Barbecuer{public:void BakeMutton()const{cout<<"烤羊肉串 ";}void BakeChickenWing()const{cout<<"烤鸡翅" ;}};#endif

 

//Command

#ifndef COMMAND_H#define COMMAND_H#include <iostream>#include <string>#include "Barbecuer.h"using std::cout;using std::endl;using std::string;class Command{public:Command(Barbecuer* b=0,int nu=0):bar(b),num(nu){}virtual ~Command(){}public:virtual void ExcuteCommand()=0;void SetBarName(string name){BarName=name;}string GetBarName()const{return BarName;}int GetNum()const{return num;}protected:Barbecuer* bar;string BarName;int num;};#endif

 

//烧烤羊肉的要求

#include "Command.h"class BakeMuttonCommand:public Command{public:BakeMuttonCommand(Barbecuer* b=0,int nu=0):Command(b,nu){SetBarName("烤羊肉串");}~BakeMuttonCommand(){}public:virtual void ExcuteCommand(){bar->BakeMutton();cout<<num<<"个"<<endl;}};//烧烤鸡翅的要求与之类似

 

 

//服务员类

//Waiter.h#pragma onceclass Command;#include <vector>using std::vector;class Waiter{public:Waiter(void);~Waiter(void);public:void SetOrder(Command* command);void CancerOrder(Command* command);void Notify();void Refresh();private:vector<Command*> vecCommands;};//Waiter.cpp#include "Waiter.h"#include "Command.h"#include <algorithm>Waiter::Waiter(void){}Waiter::~Waiter(void){}void Waiter::SetOrder(Command* command){vecCommands.push_back (command);cout<<"需要:"<<command->GetBarName() <<","<<command->GetNum ()<<"个/n";}void Waiter::CancerOrder(Command* command){ vector<Command*>::iterator iter;iter=find(vecCommands.begin (),vecCommands.end (),command);Command* com=0;if(iter!=vecCommands.end ()){ com=*iter;vecCommands.erase (iter);cout<<"取消:"<<command->GetBarName() <<","<<command->GetNum ()<<"个/n";delete com;}}void Waiter::Notify(){vector<Command*>::iterator iter=vecCommands.begin ();while(iter!=vecCommands.end ()){(*iter)->ExcuteCommand ();++iter;}Refresh();}void Waiter::Refresh(){vector<Command*>::iterator iter=vecCommands.begin ();while(iter!=vecCommands.end ()){delete *(iter++);}vecCommands.erase (vecCommands.begin (),vecCommands.end ());}

 

//主程序

#include "Waiter.h"#include "BakeChickenWingCommand.h"#include "BakeMuttonCommand.h"int main(){Waiter girl;Barbecuer* bar=new Barbecuer();Command* MuttonCommand1=new BakeChickenWingCommand(bar,10);Command* ChickenWingCommand2=new BakeChickenWingCommand(bar,4);girl.SetOrder (MuttonCommand1);girl.SetOrder (ChickenWingCommand2);girl.CancerOrder (MuttonCommand1);girl.Notify ();delete bar;return 0;}结果：需要:烤鸡翅,10个需要:烤鸡翅,4个取消:烤鸡翅,10个烤羊肉串 4个