1.命令模式简介
命令模式：将一个请求封装为一个对象，从而使得你可用不同的请求对客户进行参数化；对请求排队或者记录日志，以及支持可撤销的操作。UML类图如下：
2.实例
定义几个类模拟烧烤店烧烤场景，具体类图如下：
c 代码实现如下：
代码语言：javascript复制#include<exception>
#include <iostream>
#include<string>
#include<list>
using namespace std;
//13.命令模式：烧烤店烧烤
class Barbecuer
{
public:
void bakeMutton()
{
cout << "烤羊肉串！" << endl;
}
void bakeChickenWing()
{
cout << "烤鸡翅！" << endl;
}
};
class Command
{
public:
Command(const string &istrName) :m_strName(istrName){}
virtual ~Command(){};
void setBarbecuer(Barbecuer iBarbecuer){ m_barbecuer = iBarbecuer; }
string getName(){ return m_strName; }
virtual void ExcuteCommand() = 0;
protected:
string m_strName;
Barbecuer m_barbecuer;
};
class BakeMuttonCommand:public Command
{
public:
BakeMuttonCommand(const string &istrName) :Command(istrName){}
void ExcuteCommand()override
{
m_barbecuer.bakeMutton();
}
};
class BakeChickenWingCommand :public Command
{
public:
BakeChickenWingCommand(const string &istrName) :Command(istrName){}
void ExcuteCommand()override
{
m_barbecuer.bakeChickenWing();
}
};
class Waiter
{
public:
void addOrder(Command *ipCom)
{
m_commands.push_back(ipCom);
cout << "新增订单:" << ipCom->getName() << endl;
}
void removeOrder(Command *ipCom)
{
for (auto itr = m_commands.begin(); itr != m_commands.end(); itr)
{
if (*itr==ipCom)
{
m_commands.erase(itr);
cout << "移除订单:" << ipCom->getName() << endl;
break;
}
}
}
void notify()
{
for (auto itr = m_commands.begin(); itr != m_commands.end(); itr)
{
(*itr)->ExcuteCommand();
}
}
private:
list<Command*>m_commands;
};
int main()
{
Barbecuer barbecuer;
Command *pCom1 = new BakeMuttonCommand("烤羊肉串！");
Command *pCom2 = new BakeChickenWingCommand("烤鸡翅！");
Waiter girl;
girl.addOrder(pCom1);
girl.addOrder(pCom2);
girl.notify();
system("pause");
}
