随便写点什么

/// <summary>
    /// 业务经理
    /// </summary>
    public class Manager
    {
        private static Manager _singleManager;
        private Manager()
        {
        }
        public static Manager GetSingelManager()
        {
            if (_singleManager == null)
                _singleManager = new Manager();
            return _singleManager;
        }
        public void UpLevel(User user)
        {
            if (user.Key.UserType == CardType.Gold)
            {
                Console.WriteLine(user.UserName + ":已经是Gold用户");
                return;
            }
            user.Key.UserType += 1;
            Console.WriteLine(user.UserName + ":升级为" + user.Key.UserType);
        }
        public void DownLevel(User user)
        {
            if (user.Key.UserType == CardType.Gold)
            {
                user.Key.UserType -= 1;
                Console.WriteLine(user.UserName + ":已经降级为" + user.Key.UserType);
                return;
            }
            Console.WriteLine(user.UserName + ":已经是最低" + user.Key.UserType + "用户");
        }
    }
    /// <summary>
    /// 卡片类型
    /// </summary>
    public enum CardType
    {
        Sliver,
        Gold,
    }
    /// <summary>
    /// 用户key
    /// </summary>
    public class Key
    {
        public CardType UserType { get; set; }
        public string SoleString { get; private set; }//Key的唯一标识
        public Key(CardType e, string soleString)
        {
            UserType = e;
            SoleString = soleString;
        }
        public override string ToString()
        {
            return UserType+":"+SoleString;
        }
    }
    /// <summary>
    /// 用户获取、提交数据要实现的接口
    /// </summary>
    public interface IMyDataInterFace
    {
        string GetData();//获取数据

        bool PostData(string message);//提交数据
    }
    /// <summary>
    /// 用户类
    /// </summary>
    public class User : IMyDataInterFace
    {
        public Key Key { get; private set; }
        public string UserName { get; private set; }
        public MyServer Server { get; private set; }
        /// <summary>
        /// 初始化用户，绑定服务器
        /// </summary>
        /// <param name="key"></param>
        /// <param name="userName"></param>
        /// <param name="server"></param>
        public User(Key key, string userName,MyServer server)
        {
            Key = key;
            UserName = userName;
            this.Server = server;
        }
        public string GetData()
        {
            return Server.GetMessage(Key);
        }
        public bool PostData(string message)
        {
            if (Server.PostMessge(Key, message))
            {
                Console.WriteLine("成功提交数据");
                return true;
            }
            Console.WriteLine("提交数据失败");
            return false;
        }
    }
    /// <summary>
    /// 服务类
    /// </summary>
    public class MyServer
    {
        private static MyServer _SingleServer;
        public  Dictionary<Key, string> Dictionary { get; private set; }
        private MyServer()
        {
        }
        public static MyServer GetSingleServer()
        {
            if (_SingleServer==null)
                _SingleServer=new MyServer {Dictionary = new Dictionary<Key, string>()};
            return _SingleServer;
        }

        public string GetMessage(Key key)
        {
            var result = string.Empty;
            try
            {
                if(key.UserType==CardType.Gold)
                   result ="GoleUser:"+ Dictionary[key];
                else
                {
                    result = "SliverUser:" + Dictionary[key];
                }
                return result;
            }
            catch (Exception)
            {
                Console.WriteLine(key+"->不存在");//怎么返回key对应的用户
                return null;
            }
            
        }
        public bool PostMessge(Key key, string message)
        {
            try
            {
                Dictionary[key] = message;
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }
    }
    class Program
    {
        static  void Main(string[] args)
        {
            var server = MyServer.GetSingleServer();
            var manager = Manager.GetSingelManager();

            var key=new Key(CardType.Gold,"33520");
            var user1 = new User(key, "张三",server);
            
            var postSuccess=user1.PostData("hello");
            Console.WriteLine(user1.GetData()); 

            manager.DownLevel(user1);
            Console.WriteLine(user1.Key.UserType); 

        }
    }