職責鏈模式(Chain of Responsibility)

• 使多個物件都有機會處理請求，從而避免的發送者和接收者之間的耦合關係。將這個物件連成一條鏈，並沿著這條鏈傳遞該請求，直到有一個物件處理它為止。

基本架構圖

實例架構圖

基本程式碼

using System;

namespace DPExample
{
    abstract class Handler
    {
        protected Handler successor;

        public void SetSuccessor(Handler successor)
        {
            this.successor = successor;
        }

        public abstract void HandleRequest (int request);
    }

    class ConcreteHandler1 : Handler
    {
        public override void HandleRequest (int request)
        {
            if (request >= 0 && request < 10) {
                Console.WriteLine ("{0} 處理請求 {1}", this.GetType ().Name, request);
            } else if (successor != null) {
                successor.HandleRequest(request);
            }
        }
    }
    
    class ConcreteHandler2 : Handler
    {
        public override void HandleRequest (int request)
        {
            if (request >= 10 && request < 20) {
                Console.WriteLine ("{0} 處理請求 {1}", this.GetType ().Name, request);
            } else if (successor != null) {
                successor.HandleRequest(request);
            }
        }
    }

    
    class ConcreteHandler3 : Handler
    {
        public override void HandleRequest (int request)
        {
            if (request >= 20 && request < 30) {
                Console.WriteLine ("{0} 處理請求 {1}", this.GetType ().Name, request);
            } else if (successor != null) {
                successor.HandleRequest(request);
            }
        }
    }
}

using System;

namespace DPExample
{
 public class Program
 {
  static void Main ()
        {
            Handler h1 = new ConcreteHandler1 ();
            Handler h2 = new ConcreteHandler2 ();
            Handler h3 = new ConcreteHandler3 ();
            h1.SetSuccessor (h2);
            h2.SetSuccessor (h3);

            int[] requests = {2,5,14,22,18,3,27,20};

            foreach (int request in requests) {
                h1.HandleRequest(request);
            }
  }
 }
}

實例程式碼

using System;

namespace DPExample
{
    class 申請
    {
        private string requestType;
        public string 申請類別 {
            get { return requestType; }
            set { requestType = value; }
        }

        private string requestContent;
        public string 申請內容 {
            get { return requestContent; }
            set { requestContent = value; }
        }

        private int number;
        public int 數量 {
            get { return number; }
            set { number = value; }
        }
    }

    abstract class 管理者
    {
        protected string name;
        protected 管理者 superior;

        public 管理者(string name)
        {
            this.name = name;
        }

        public void 設定上級管理者(管理者 superior)
        {
            this.superior = superior;
        }

        abstract public void 處理請求(申請 request);
    }

    class 經理 : 管理者
    {
        public 經理 (string name) : base(name)
        {
        }

        public override void 處理請求 (申請 request)
        {
            if (request.申請類別 == "請假" && request.數量 <= 2)
                Console.WriteLine ("{0}:{1} 數量{2} 被批准", name, request.申請內容, request.數量);
            else {
                if (superior != null)
                    superior.處理請求(request);
            }
        }
    }

    class 總監 : 管理者
    {
        public 總監 (string name) : base(name)
        {
        }

        public override void 處理請求 (申請 request)
        {
            if (request.申請類別 == "請假" && request.數量 <= 5)
                Console.WriteLine ("{0}:{1} 數量{2} 被批准", name, request.申請內容, request.數量);
            else {
                if (superior != null)
                    superior.處理請求(request);
            }
        }
    }

    class 總經理 : 管理者
    {
        public 總經理 (string name) : base(name)
        {
        }

        public override void 處理請求 (申請 request)
        {
            if (request.申請類別 == "請假")
                Console.WriteLine ("{0}:{1} 數量{2} 被批准", name, request.申請內容, request.數量);
            else if (request.申請類別 == "加薪" && request.數量 <= 500)
                Console.WriteLine("{0}:{1} 數量{2} 被批准", name, request.申請內容, request.數量);
            else if (request.申請類別 == "加薪" && request.數量 > 500)
                Console.WriteLine("{0}:{1} 數量{2} 再說吧", name, request.申請內容, request.數量);
        }
    }
}

using System;


namespace DPExample
{
 public class Program
 {
  static void Main ()
        {
            經理 jinli = new 經理("金利");
            總監 zongjian = new 總監("宗劍");
            總經理 zhongjingli = new 總經理("鐘精勵");
            jinli.設定上級管理者(zongjian);
            zongjian.設定上級管理者(zhongjingli);

            申請 request = new 申請();
            request.申請類別 = "請假";
            request.申請內容 = "小菜請假";
            request.數量 = 1;
            jinli.處理請求(request);

            申請 request2 = new 申請();
            request2.申請類別 = "請假";
            request2.申請內容 = "小菜請假";
            request2.數量 = 4;
            jinli.處理請求(request2);

            申請 request3 = new 申請();
            request3.申請類別 = "加薪";
            request3.申請內容 = "小菜請求加薪";
            request3.數量 = 500;
            jinli.處理請求(request3);

            申請 request4 = new 申請();
            request4.申請類別 = "加薪";
            request4.申請內容 = "小菜請求加薪";
            request4.數量 = 1000;
            jinli.處理請求(request4);

  }

 }
}