责任链模式

深藏阁楼爱情的钟 2021-09-17 00:04 403阅读 0赞

## 17.责任链模式 ##

![70][]

public class PurchaseRequest// 采购请求
        {
            
            public double Amount { get; set; }// 金额
            public string ProductName { get; set; }
            public PurchaseRequest(double amount, string productName)
            {
                Amount = amount;
                ProductName = productName;
            }
        }
        public abstract class Approver// 审批人,Handler
        {
            public Approver NextApprover { get; set; }
            public string Name { get; set; }
            public Approver(string name)
            {
                Name = name;
            }
            public abstract void ProcessRequest(PurchaseRequest request);
        }
        public class Manager : Approver
        {
            public Manager(string name): base(name) { }
            public override void ProcessRequest(PurchaseRequest request)
            {
                if (request.Amount < 10000.0)
                {
                    Console.WriteLine("{0}-{1}  想买  {2}", this, Name, request.ProductName);
                }
                else if (NextApprover != null)
                {
                    NextApprover.ProcessRequest(request);
                }
            }
        }
        public class VicePresident : Approver// ConcreteHandler,副总
        {
            public VicePresident(string name): base(name) { }
            public override void ProcessRequest(PurchaseRequest request)
            {
                if (request.Amount < 25000.0)
                {
                    Console.WriteLine("{0}-{1}  想买  {2}", this, Name, request.ProductName);
                }
                else if (NextApprover != null)
                {
                    NextApprover.ProcessRequest(request);
                }
            }
        }
        public class President : Approver// ConcreteHandler，总经理
        {
            public President(string name): base(name) { }
            public override void ProcessRequest(PurchaseRequest request)
            {
                if (request.Amount < 100000.0)
                {
                    Console.WriteLine("{0}-{1}  想买  {2}", this, Name, request.ProductName);
                }
                else
                {
                    Console.WriteLine("Request需要组织一个会议讨论");
                }
            }
        }
        class Program
        {
            static void Main(string[] args)
            {
                PurchaseRequest requestTelphone = new PurchaseRequest(4000.0, "手机");
                PurchaseRequest requestSoftware = new PurchaseRequest(10000.0, "软件");
                PurchaseRequest requestComputers = new PurchaseRequest(40000.0, "电脑");
    
                Approver manager = new Manager("张三");
                Approver Vp = new VicePresident("李四");
                Approver Pre = new President("王五");
            
                manager.NextApprover = Vp;// 设置责任链
                Vp.NextApprover = Pre;
    
                manager.ProcessRequest(requestTelphone); // 处理请求
                manager.ProcessRequest(requestSoftware);
                manager.ProcessRequest(requestComputers);
                Console.ReadLine();
            }
        }

![70 1][]

[70]: /images/20210725/dd4d721ac1d641babf57303882c1ed51.png
[70 1]: /images/20210725/5fa3923565b446909779f2812a23ae6a.png