设计模式---命令模式

定义

命令模式(Command Pattern)：将一个请求封装为一个对象，从而使我们可用不同的请求对客户进行参数化；对请求排队或者记录请求日志，以及支持可撤销的操作。命令模式是一种对象行为型模式，其别名为动作(Action)模式或事务(Transaction)模式。

模式结构

命令模式包含如下角色：

• Command: 抽象命令类
• ConcreteCommand: 具体命令类
• Invoker: 调用者
• Receiver: 接收者
• Client:客户类

时序图

 

代码

#include <iostream>
#include "ConcreteCommand.h"
#include "Invoker.h"
#include "Receiver.h"

using namespace std;

int main(int argc, char *argv[])
{
    Receiver * pReceiver = new Receiver();
    ConcreteCommand * pCommand = new ConcreteCommand(pReceiver);
    Invoker * pInvoker = new Invoker(pCommand);
    pInvoker->call();
    
    delete pReceiver;
    delete pCommand;
    delete pInvoker;
    return 0;
}
///////////////////////////////////////////////////////////
//  Receiver.h
//  Implementation of the Class Receiver
//  Created on:      07-十月-2014 17:44:02
//  Original author: colin
///////////////////////////////////////////////////////////

#if !defined(EA_8E5430BB_0904_4a7d_9A3B_7169586237C8__INCLUDED_)
#define EA_8E5430BB_0904_4a7d_9A3B_7169586237C8__INCLUDED_

class Receiver
{
public:
    Receiver();
    virtual ~Receiver();
    void action();
};
#endif // !defined(EA_8E5430BB_0904_4a7d_9A3B_7169586237C8__INCLUDED_)
///////////////////////////////////////////////////////////
//  Receiver.cpp
//  Implementation of the Class Receiver
//  Created on:      07-十月-2014 17:44:02
//  Original author: colin
///////////////////////////////////////////////////////////

#include "Receiver.h"
#include <iostream>
using namespace std;

Receiver::Receiver(){
}

Receiver::~Receiver(){
}

void Receiver::action(){
    cout << "receiver action." << endl;
}
///////////////////////////////////////////////////////////
//  ConcreteCommand.h
//  Implementation of the Class ConcreteCommand
//  Created on:      07-十月-2014 17:44:01
//  Original author: colin
///////////////////////////////////////////////////////////

#if !defined(EA_1AE70D53_4868_4e81_A1B8_1088DA355C23__INCLUDED_)
#define EA_1AE70D53_4868_4e81_A1B8_1088DA355C23__INCLUDED_

#include "Command.h"
#include "Receiver.h"

class ConcreteCommand : public Command
{

public:
    ConcreteCommand(Receiver * pReceiver);
    virtual ~ConcreteCommand();
    virtual void execute();
private:
    Receiver *m_pReceiver;
};
#endif // !defined(EA_1AE70D53_4868_4e81_A1B8_1088DA355C23__INCLUDED_)
///////////////////////////////////////////////////////////
//  ConcreteCommand.cpp
//  Implementation of the Class ConcreteCommand
//  Created on:      07-十月-2014 17:44:02
//  Original author: colin
///////////////////////////////////////////////////////////

#include "ConcreteCommand.h"
#include <iostream>
using namespace std;


ConcreteCommand::ConcreteCommand(Receiver *pReceiver){
    m_pReceiver = pReceiver;
}

ConcreteCommand::~ConcreteCommand(){

}

void ConcreteCommand::execute(){
    cout << "ConcreteCommand::execute"  << endl;
    m_pReceiver->action();
}
///////////////////////////////////////////////////////////
//  Invoker.h
//  Implementation of the Class Invoker
//  Created on:      07-十月-2014 17:44:02
//  Original author: colin
///////////////////////////////////////////////////////////

#if !defined(EA_3DACB62A_0813_4d11_8A82_10BF1FB00D9A__INCLUDED_)
#define EA_3DACB62A_0813_4d11_8A82_10BF1FB00D9A__INCLUDED_

#include "Command.h"

class Invoker
{

public:
    Invoker(Command * pCommand);
    virtual ~Invoker();
    void call();

private:
    Command *m_pCommand;


};
#endif // !defined(EA_3DACB62A_0813_4d11_8A82_10BF1FB00D9A__INCLUDED_)
///////////////////////////////////////////////////////////
//  Invoker.cpp
//  Implementation of the Class Invoker
//  Created on:      07-十月-2014 17:44:02
//  Original author: colin
///////////////////////////////////////////////////////////

#include "Invoker.h"
#include <iostream>
using namespace std;

Invoker::Invoker(Command * pCommand){
    m_pCommand = pCommand;
}

Invoker::~Invoker(){

}

void Invoker::call(){
    cout << "invoker calling" << endl;
    m_pCommand->execute();
}