【設計模式】之命令模式

• UML

• 舉例

//烤肉串者
    public class Barbecuer
    {
        public void BakeMutton()
        {
            Console.WriteLine("烤羊肉串");
        }
        public void BakeChickenWing()
        {
            Console.WriteLine("烤雞翅");
        }
    }

//抽象命令
    abstract class Command
    {
        protected Barbecuer receiver;
        
        public Command(Barbecuer receiver)
        {
            this.receiver = receiver;
        }
        abstract public void ExcuteCommand();
    }

//烤羊肉串命令
    class BakeMuttonCommand : Command
    {
        public BakeMuttonCommand(Barbecuer receiver) : base(receiver)
        {
        }

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

//烤雞翅命令
    class BakeChickenWingCommand : Command
    {
        public BakeChickenWingCommand(Barbecuer receiver) : base(receiver)
        {
        }

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

class Waiter
    {
        private IList<Command> commandList = new List<Command>();
        //設置訂單
        public void SetOrder(Command command)
        {
            if (command.ToString().Equals("Test28.BakeMuttonCommand"))
            {
                Console.WriteLine("羊肉串賣完了！");
            }
            else
            {
                this.commandList.Add(command);
                Console.WriteLine("增加訂單：" + command.ToString() + " 時間：" + DateTime.Now.ToString());
            }
            
        }
        //取消訂單
        public void CancelCommand(Command command)
        {
            commandList.Remove(command);
            Console.WriteLine("取消訂單：" + command.ToString() + " 時間：" + DateTime.Now.ToString());
        }
        //通知執行
        public void Notify()
        {
            foreach(Command command in commandList)
            {
                command.ExcuteCommand();
            }
        }
    }

class Program
    {
        static void Main(string[] args)
        {
            Barbecuer barbecuer = new Barbecuer();
            Waiter waiter = new Waiter();
            BakeChickenWingCommand bcwc = new BakeChickenWingCommand(barbecuer);
            BakeMuttonCommand bmc = new BakeMuttonCommand(barbecuer);

            waiter.SetOrder(bcwc);
            waiter.SetOrder(bmc);
            waiter.CancelCommand(bcwc);
            waiter.Notify();
        }
    }