设计模式 - Command

意图：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，以及支持可撤消的操作。

class Receiver
{
public:
    Receiver()
    {}
    virtual ~Receiver()
    {}
    virtual void Action()
    {
        cout<<"Receiver::Action()"<<endl;
    }
};

class Command
{
public:
    Command()
    {}
    virtual ~Command()
    {}
    virtual void Execute() = 0;
};

class ConcreteCommand: public Command
{
public:
    ConcreteCommand(Receiver* receiver)
    {
        this->receiver = receiver;
    }
    ~ConcreteCommand()
    {}
    void Execute()
    {
        cout<<"ConcreteCommand::Execute()"<<endl;
        receiver->Action();
    }

private:
    Receiver* receiver;
};

class Invoker
{
public:
    Invoker(Command* cmd)
    {
        this->cmd = cmd;
    }
    ~Invoker()
    {}
    void Invoke()
    {
        cmd->Execute();
    }

private:
    Command* cmd;
};