命令模式 -- 大话设计模式

在今天，读书有时是件“麻烦”事。它需要你付出时间，付出精力，还要付出一份心境。--仅以《大话设计模式》来祭奠那逝去的……

命令模式：将一个请求封装成一个对象，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，以及支持可撤销操作

1.烧烤店就餐

　　烧烤男孩和服务员女孩，开门营业，客户点餐，女孩记单，客人点完菜，女孩通知男孩开做

　　定义烧烤师傅类

    /// <summary>
    /// 烤肉串师傅类
    /// </summary>
    public class Barbecuer
    {
        public void BakeMutton()
        {
            Console.WriteLine("烤羊肉串");
        }

        public void BakeChickenWing()
        {
            Console.WriteLine("烤鸡翅");
        }   
    }

 　　定义抽象命令类和具体命令类

    /// <summary>
    /// 抽象命令
    /// </summary>
    public abstract class Command
    {
        protected Barbecuer receiver;

        public Command(Barbecuer receiver)
        {
            this.receiver = receiver;
        }

        public abstract void ExcuteCommand();
    }

    /// <summary>
    /// 烤肉命令
    /// </summary>
    public class BakeMuttonCommand : Command
    {
        public BakeMuttonCommand(Barbecuer receiver) : base(receiver) { }

        public override void ExcuteCommand()
        {
            receiver.BakeMutton();
        }
    }

    /// <summary>
    /// 烤肉命令
    /// </summary>
    public class BakeChickenWingCommand : Command
    {
        public BakeChickenWingCommand(Barbecuer receiver) : base(receiver) { }

        public override void ExcuteCommand()
        {
            receiver.BakeChickenWing();
        }
    }

 　　定义服务员类

    /// <summary>
    /// 服务员
    /// </summary>
    public class Waiter
    {
        private IList<Command> orders = new List<Command>();

        /// <summary>
        /// 设置订单
        /// </summary>
        public void SetOrder(Command command)
        {
            orders.Add(command);
            Console.WriteLine("增加订单：{0}；时间：{1}", command.ToString(), DateTime.Now);
        }

        /// <summary>
        /// 取消订单
        /// </summary>
        public void CancleOrder(Command command)
        {
            orders.Remove(command);
            Console.WriteLine("取消订单：{0}；时间：{1}", command.ToString(), DateTime.Now);
        }

        /// <summary>
        /// 全部通知
        /// </summary>
        public void Notify()
        {
            foreach (var v in orders)
            {
                v.ExcuteCommand();
            }
        }
    }

 　　开启场景模拟

        static void Main(string[] args)
        {
            //烧烤男孩和服务员女孩
            Barbecuer boy = new Barbecuer();
            Waiter girl = new Waiter();

            //开门营业，客户点餐，女孩记单
            girl.SetOrder(new BakeMuttonCommand(boy));
            girl.SetOrder(new BakeChickenWingCommand(boy));

            //客人点完菜，女孩通知男孩开做
            girl.Notify();
        }