C#设计模式之二十职责链模式（Chain of Responsibility Pattern）【行为型】

  1 namespace ChainOfResponsibility
  2 {
  3     // 采购请求
  4     public sealed class PurchaseRequest
  5     {
  6         // 金额
  7         public double Amount { get; set; }
  8 
  9         // 产品名字
 10         public string ProductName { get; set; }
 11 
 12         public PurchaseRequest(double amount, string productName)
 13         {
 14             Amount = amount;
 15             ProductName = productName;
 16         }
 17     }
 18  
 19     //抽象审批人,Handler---相当于“抽象处理者角色”
 20     public abstract class Approver
 21     {
 22         //下一位审批人，由此形成一条链
 23         public Approver NextApprover { get; set; }
 24 
 25         //审批人的名称
 26         public string Name { get; set; }
 27 
 28         public Approver(string name)
 29         {
 30             this.Name = name;
 31         }
 32 
 33         //处理请求
 34         public abstract void ProcessRequest(PurchaseRequest request);
 35     }
 36  
 37     //部门经理----相当于“具体处理者角色” ConcreteHandler
 38     public sealed class Manager : Approver
 39     {
 40         public Manager(string name): base(name){ }
 41  
 42         public override void ProcessRequest(PurchaseRequest request)
 43         {
 44             if (request.Amount <= 10000.0)
 45             {
 46                 Console.WriteLine("{0} 部门经理批准了对原材料{1}的采购计划！", this.Name, request.ProductName);
 47             }
 48             else if (NextApprover != null)
 49             {
 50                 NextApprover.ProcessRequest(request);
 51             }
 52         }
 53     }
 54  
 55     //财务经理---相当于“具体处理者角色”ConcreteHandler
 56     public sealed class FinancialManager : Approver
 57     {
 58         public FinancialManager(string name): base(name){ }
 59 
 60         public override void ProcessRequest(PurchaseRequest request)
 61         {
 62             if (request.Amount > 10000.0 && request.Amount <= 50000.0)
 63             {
 64                 Console.WriteLine("{0} 财务经理批准了对原材料{1}的采购计划！", this.Name, request.ProductName);
 65             }
 66             else if (NextApprover != null)
 67             {
 68                 NextApprover.ProcessRequest(request);
 69             }
 70         }
 71     }
 72  
 73     //总裁---相当于“具体处理者角色” ConcreteHandler
 74     public sealed class CEO :Approver
 75     {
 76         public CEO(string name): base(name){ }
 77 
 78         public override void ProcessRequest(PurchaseRequest request)
 79         {
 80             if (request.Amount > 50000.0 && request.Amount < 300000.0)
 81             {
 82                 Console.WriteLine("{0} 总裁批准了对原材料 {1} 的采购计划！", this.Name, request.ProductName);
 83             }
 84             else
 85             {
 86                 Console.WriteLine("这个采购计划的金额比较大，需要一次董事会会议讨论才能决定！");
 87             }
 88         }
 89     }
 90  
 91     class Program
 92     {
 93         static void Main(string[] args)
 94         {
 95             PurchaseRequest requestDao = new PurchaseRequest(8000.0, "单刀5把");
 96             PurchaseRequest requestHuaJi = new PurchaseRequest(10000.0, "10把方天画戟");
 97             PurchaseRequest requestJian = new PurchaseRequest(80000.0, "5把金丝龙鳞闪电劈");
 98  
 99             Approver manager = new Manager("黄飞鸿");
100             Approver financial = new FinancialManager("黄麒英");
101             Approver ceo = new CEO("十三姨");
102  
103             // 设置职责链
104             manager.NextApprover = financial;
105             financial.NextApprover = ceo;
106  
107             // 处理请求
108             manager.ProcessRequest(requestDao);
109             manager.ProcessRequest(requestHuaJi);
110             manager.ProcessRequest(requestJian);
111 
112             Console.ReadLine();
113         }
114     }
115 }