using System;  /**//// <summary> ///售貨員接口,所有類型的售貨員必須實現該接口 /// </summary> interface ISalesMan {   string Name {set;get;} //售貨員名字   void SetNext(ISalesMan nextSalesMan); //設置下一級售貨員   void Process(Order order); //處理訂單 }  /**//// <summary> /// 訂單類 /// </summary> class Order {   private int orderAmount;    public int Amount   {     set{ this.orderAmount = value;}     get{ return this.orderAmount; }   } }  /**//// <summary> /// 一類售貨員 /// </summary> class FirstSalesMan : ISalesMan {   private ISalesMan nextSalesMan = null;   private string name = string.Empty;    ISalesMan 成員ISalesMan 成員 }  /**//// <summary> /// 二類售貨員 /// </summary> class SecondSalesMan : ISalesMan {   private ISalesMan nextSalesMan = null;   private string name = string.Empty;    ISalesMan 成員ISalesMan 成員 }  /**//// <summary> /// 三類售貨員 /// </summary> class ThirdSalesMan : ISalesMan {   private ISalesMan nextSalesMan = null;   private string name = string.Empty;    ISalesMan 成員ISalesMan 成員 }  class Client {   public static void Main(string[] args)   {     FirstSalesMan first = new FirstSalesMan();     first.Name = "firstMan";      SecondSalesMan second = new SecondSalesMan();     second.Name = "secondMan";      ThirdSalesMan third = new ThirdSalesMan();     third.Name = "thirdMan";      first.SetNext(second);     second.SetNext(third);      Order o = new Order();     o.Amount = 300;     first.Process(o);      o = new Order();     o.Amount = 1300;     first.Process(o);      o = new Order();     o.Amount = 11300;     first.Process(o);      Console.Read();   } }