职责链模式
前言
职责链模式（Chain of Responsibility）:使多个对象都有机会处理请求，从而避免请求的发送者和接收者之间的耦合关系。将这个对象连成一条链，并沿着这条链传递该请求，直到有一个对象处理它为止。
一、申请类
1 public class Request
2 {
3 public string RequestType { get; set; }
4 public string RequestContent { get; set; }
5 public int Number { get; set; }
6 }
二、管理者抽象类
1 public abstract class Manager
2 {
3 protected string name;
4 //管理者的上级
5 protected Manager superior;
6 public Manager(string name)
7 {
8 this.name = name;
9 }
10 //设置管理者的上级
11 public void SetSuperior(Manager superior)
12 {
13 this.superior = superior;
14 }
15 //申请请求
16 public abstract void RequestApplication(Request request);
17 }
三、具体的管理类
1 //经理类
2 public class CommonManager : Manager
3 {
4 public CommonManager(string name) : base(name)
5 {
6 }
7 public override void RequestApplication(Request request)
8 {
9 //经理所能有的权限就是可批准下属两天内的假期
10 if (request.RequestType == "请假" && request.Number <= 2)
11 {
12 Console.WriteLine("{0}:{1} 数量{2} 被比准", name, request.RequestContent, request.Number);
13 }
14 else
15 {
16 //其余的申请都需要转到上级
17 if (superior != null)
18 {
19 superior.RequestApplication(request);
20 }
21 }
22 }
23 }
1 //总监
2 public class Majordomo : Manager
3 {
4 public Majordomo(string name) : base(name)
5 {
6 }
7
8 public override void RequestApplication(Request request)
9 {
10 //总监所能有的权限就是可批准下属一周内的假期
11 if (request.RequestType == "请假" && request.Number <= 5)
12 {
13 Console.WriteLine("{0}:{1} 数量{2} 被比准", name, request.RequestContent, request.Number);
14 }
15 else
16 {//其余的申请都需要转到上级
17 if (superior != null)
18 {
19 superior.RequestApplication(request);
20 }
21 }
22 }
23 }
1 //总经理
2 public class GeneralManager : Manager
3 {
4 public GeneralManager(string name) : base(name)
5 {
6 }
7
8 public override void RequestApplication(Request request)
9 {
10 if (request.RequestType == "请假")
11 {
12 Console.WriteLine("{0}:{1} 数量{2} 被比准", name, request.RequestContent, request.Number);
13 }
14 else if (request.RequestType == "加薪" && request.Number <= 500)
15 {
16 Console.WriteLine("{0}:{1} 数量{2} 被比准", name, request.RequestContent, request.Number);
17 }
18 else if (request.RequestType == "加薪" && request.Number > 500)
19 {
20 Console.WriteLine("{0}:{1} 数量{2} 滚蛋吧你", name, request.RequestContent, request.Number);
21 }
22 }
23 }
四、客户端
1 class Program
2 {
3 static void Main(string[] args)
4 {
5 CommonManager nini = new CommonManager("剑圣");
6 Majordomo dada = new Majordomo("夫子");
7 GeneralManager yeye = new GeneralManager("昊天");
8
9 //设置上级，可以根据实际需求更改
10 nini.SetSuperior(dada);
11 dada.SetSuperior(yeye);
12
13
14 /*
15 * 客户端的申请都是由 ’经理‘ 发起，但实际谁来决策由具体管理类来处理，客户端不知道
16 */
17 Request request = new Request();
18 request.RequestType = "请假";
19 request.RequestContent = "剑圣娶亲";
20 request.Number = 1;
21 nini.RequestApplication(request);
22
23 Request request2 = new Request();
24 request2.RequestType = "请假";
25 request2.RequestContent = "夫子娶亲";
26 request2.Number = 1;
27 nini.RequestApplication(request2);
28
29 Request request3 = new Request();
30 request3.RequestType = "加薪";
31 request3.RequestContent = "夫子加钱";
32 request3.Number = 500;
33 nini.RequestApplication(request3);
34
35 Request request4 = new Request();
36 request4.RequestType = "加薪";
37 request4.RequestContent = "昊天加钱";
38 request4.Number = 1000;
39 nini.RequestApplication(request4);
40
41 Console.ReadKey();
42 }
43 }
总结
1、最关键的是当客户提交一个请求时，请求是沿链传递直至一个ConcreteHandler对象负责处理它。
2、接收者和发送者都没有对方的明确信息，且链中的对象自己也并不知道链的结构。结果是职责链可简化对象的相互连接，他们仅需保持一个向其后继者的引用，而不需保持它所有的候选接受者的引用。
参考书籍：大话设计模式
