责任链模式

定义

 public interface IHandler
 {
     public IHandler next { get; set; }
     void Response();
 }

 public class HandlerOne : IHandler
 {
     public IHandler next { get; set; }

     public void Response()
     {
         Console.WriteLine("正在处理程序1");
         if (next != null) next.Response();
         else Console.WriteLine("处理完成");
     }
 }
 public class HandlerTwo: IHandler
 {
     public IHandler next { get; set; }

     public void Response()
     {
         Console.WriteLine("正在处理程序2");
         if (next != null) next.Response();
         else Console.WriteLine("处理完成");
     }
 }
 public class HandlerThree : IHandler
 {
     public IHandler next { get; set; }

     public void Response()
     {
         Console.WriteLine("正在处理程序3");
         if (next != null) next.Response();
         else Console.WriteLine("处理完成");
     }
 }

调用

    Console.WriteLine("责任链模式");
    HandlerOne handlerOne = new HandlerOne();
    HandlerTwo handlerTwo = new HandlerTwo();
    HandlerThree handlerThree = new HandlerThree();
    handlerOne.next = handlerTwo;
    handlerTwo.next = handlerThree;
    handlerOne.Response();