后台单用户在线，简单处理

        /// <summary>
        /// 在线处理数据结构
        /// </summary>
        [Serializable]
        public class OnlineData
        {
            /// <summary>
            /// 在线用户ID
            /// </summary>
            public int UserID { get; set; }
            /// <summary>
            /// 上线时间
            /// </summary>
            public string Timer { get; set; }
        }

方法预览

 

1.当前程序所有的在线用户，单例存在

    /// <summary>
    /// 后台单用户在线，简单处理
    /// </summary>
    public class B_UserOnline
    {
        /// <summary>
        /// 存储已经登录的用户UserID，和对应的登录时间
        /// </summary>
        private static List<OnlineData> _UserIDList = new List<OnlineData>();
        private IB_User IB_User = ConcreteFactory.GetB_User();

        #region 获取
        /// <summary>
        /// 获取上线用户数量
        /// </summary>
        /// <returns></returns>
        public int GetCount()
        {
            return _UserIDList.Count;
        }
        /// <summary>
        /// 获取登录用户的信息UserID+登录编号
        /// </summary>
        /// <returns></returns>
        public static List<OnlineData> GetList()
        {
            return _UserIDList;
        }
        /// <summary>
        /// 获取上线用户ID列表
        /// </summary>
        /// <returns></returns>
        public List<int> GetUserIDList()
        {
            return _UserIDList.Select(q => q.UserID).ToList() ;
        }
        /// <summary>
        /// 获取数据项
        /// </summary>
        /// <param name="UserID">用户ID</param>
        /// <returns></returns>
        public static OnlineData GetByUserID(int UserID)
        {
            return _UserIDList.FirstOrDefault(q => q.UserID == UserID);
        }
        /// <summary>
        /// 获取在线用户对象列表
        /// </summary>
        /// <returns></returns>
        public List<B_User> GetUserList()
        {
            List<B_User> userList = new List<B_User>();
            foreach (var item in _UserIDList)
            {
                B_User user = IB_User.GetByID(item.UserID);
                if (user != null)
                    userList.Add(user);
            }
            return userList;
        }
        #endregion

        #region 操作
        /// <summary>
        /// 判断用户是否已经上线
        /// </summary>
        /// <param name="UserID">上线用户ID</param>
        /// <returns></returns>
        public bool IsOnline(int UserID, string Timer)
        {
            return _UserIDList.Any(q => q.UserID == UserID && q.Timer == Timer);
        }
        /// <summary>
        /// 判断用户是否在线上
        /// </summary>
        /// <param name="UserID"></param>
        /// <returns></returns>
        public bool IsOnline(int UserID)
        {
            return _UserIDList.Any(q => q.UserID == UserID);
        }
        /// <summary>
        /// 添加上线用户
        /// </summary>
        /// <param name="UserID">上线用户ID</param>
        public bool Add(int UserID, string Timer)
        {
            if (IsOnline(UserID, Timer) == false)
            {
                _UserIDList.Add(new OnlineData() {
                    UserID=UserID,
                    Timer=Timer
                });
                return true;
            }
            return false;
        }
        /// <summary>
        /// 添加上线用户
        /// </summary>
        /// <param name="user">用户对象</param>
        /// <param name="auto">是否自动登录</param>
        /// <returns></returns>
        public bool Add(B_User user, string auto = "0")
        {
            lock (this.GetType())
            {
                //如果已经在线，返回登录失败
                if (IsOnline(user.UserID))
                    return false;
                //1.生成用户的登录编号,用户登录上线
                //int Timer = Convert.ToInt32(DateTime.Now.ToString("MMddhhmmss"));
                string Timer = DateTime.Now.ToString("yyyyMMddhhmmssms");
                Add(user.UserID, Timer);
                //2.保存信息，到客户端
                //保存用户ID，用户名 到浏览器
                B_UserHelper.SetCookie(user, Timer, auto);
                //3.添加登录记录
                B_UserHelper.AddLoginInfo(user.UserID);
                return true;
            }
        }
        /// <summary>
        /// 删除用户,下线
        /// </summary>
        /// <param name="UserID">下线用户ID</param>
        /// <param name="isClear">指定是否，清空用户的客户端信息</param>
        public bool Remove(int UserID, bool isClear = false)
        {
            if (IsOnline(UserID))
            {
                //2.添加退出记录
                B_UserHelper.AddLogoffInfo(UserID);
                //1.移除在线用户
                _UserIDList.Remove(GetByUserID(UserID));
                //3.清除cookie
                if (isClear)
                    B_UserHelper.ClearCookie();
                return true;
            }
            return false;
        }
        #endregion

        #region 网站启动操作
        /// <summary>
        /// 网站停止，保存数据到磁盘
        /// </summary>
        public void SaveList()
        {
            string filename = GetFileName();
            try
            {
                XmlSerializerHelper _serialize = new XmlSerializerHelper(filename);
                _serialize.XmlSerialize<List<OnlineData>>(_UserIDList);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        /// <summary>
        /// 网站启动，从磁盘读取数据
        /// </summary>
        public void LoadList()
        {
            string filename = GetFileName();
            try
            {
                XmlSerializerHelper _serialize = new XmlSerializerHelper(filename);
                _UserIDList = _serialize.XmlDeserialize<List<OnlineData>>();
            }
            catch (Exception)
            {
                _UserIDList = new List<OnlineData>();
            }
        }
        /// <summary>
        /// 存储的文件位置
        /// </summary>
        /// <returns></returns>
        private string GetFileName()
        {
            string filename = ConfigValue.DataPath + "userList.xml";
            //string filename ="";
            if (File.Exists(filename) == false)
            {
                File.Create(filename).Close();
            }
            return filename;
        }
        #endregion

        /// <summary>
        /// 在线处理数据机构
        /// </summary>
        [Serializable]
        public class OnlineData
        {
            /// <summary>
            /// 在线用户ID
            /// </summary>
            public int UserID { get; set; }
            /// <summary>
            /// 上线时间
            /// </summary>
            public string Timer { get; set; }
        }
    }