《大话设计模式》学习笔记20:职责链模式
申请审批示例:
1.请求类:
public class Request { public string RequestType { get; set; } public string RequestContent { get; set; } public int Number { get; set; } }
2.Handler:
public abstract class Manager { protected string name; protected Manager superiorManager; public Manager(string name) { this.name = name; } public void SetSuperior(Manager superiorManager) { this.superiorManager = superiorManager; } public abstract void RequestApplication(Request request); }
3.ConcreteHandler:
public class CommonManager:Manager { public CommonManager(string name) :base(name) { } public override void RequestApplication(Request request) { if(request.RequestType=="请假"&&request.Number<=2) { Console.WriteLine("{0}:{1} 数量{2} 被批准", name, request.RequestType, request.Number); } else { if(superiorManager!=null) { superiorManager.RequestApplication(request); } } } }
public class Majordomo:Manager { public Majordomo(string name) :base(name) { } public override void RequestApplication(Request request) { if(request.RequestType=="请假"&&request.Number<=5) { Console.WriteLine("{0}:{1} 数量{2} 被批准", name, request.RequestType, request.Number); } else { if(superiorManager!=null) { superiorManager.RequestApplication(request); } } } }
public class GeneralManager:Manager { public GeneralManager(string name) :base(name) { } public override void RequestApplication(Request request) { if(request.RequestType=="请假") { Console.WriteLine("{0}:{1} 数量{2} 被批准", name, request.RequestType, request.Number); } else if(request.RequestType=="加薪") { if (request.Number <= 500) { Console.WriteLine("{0}:{1} 数量{2} 被批准", name, request.RequestType, request.Number); } else { Console.WriteLine("{0}:{1} 数量{2} 再说吧", name, request.RequestType, request.Number); } } } }
客户端代码:
class Program { static void Main(string[] args) { Manager commonManager = new CommonManager("经理"); Manager majordom = new Majordomo("总监"); Manager generalManager = new GeneralManager("总经理"); commonManager.SetSuperior(majordom); majordom.SetSuperior(generalManager); Request request = new Request(); request.RequestType = "请假"; request.RequestContent = "事假"; request.Number = 1; commonManager.RequestApplication(request); request.RequestType = "请假"; request.RequestContent = "年假"; request.Number = 4; commonManager.RequestApplication(request); request.RequestType = "加薪"; request.RequestContent = "加薪一千"; request.Number = 1000; commonManager.RequestApplication(request); } }
优点:接收者和发送者都没有对方的明确信息,且链中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,它们仅需保持一个指向其后继者的引用,而不需要保持它所有候选接受者的引用。
posted on 2015-05-25 21:37 Walden1024 阅读(288) 评论(0) 编辑 收藏 举报