/// <summary>
    /// 用户授权校验结果
    /// </summary>
    public class UserLicenseInfo
    {
        /// <summary>
        /// 校验的Mac地址
        /// </summary>
        public string ValidMacAddress { get; set; }

        /// <summary>
        /// 软件过期日期
        /// </summary>
        public DateTime ExpireTime { get; set; }

        /// <summary>
        /// 软件是否过期
        /// </summary>
        public bool IsExpired { get; set; }

        /// <summary>
        /// 软件剩余天数
        /// </summary>
        public double DaysRemaining { get; set; }

        /// <summary>
        /// 校验结果信息
        /// </summary>
        public string ValidateResult { get; set; }
    }

    /// <summary>
    /// Mac地址+白名单用户，授权策略
    /// </summary>
    internal class MacBlacklistProvider : IUserLicenseProvider
    {
        //授权的用户列表
        internal static List<sys_ClientWhiteList> _Cache = null;

        private UserLicenseInfo _LicenseInfo = null;

        public UserLicenseInfo LicenseInfo
        {
            get { return _LicenseInfo; }
        }

        /// <summary>
        /// 检查用户授权是否过期
        /// </summary>
        /// <exception cref="BizException"></exception>
        public void Check()
        {
            if (IsExpired())
            {
                throw new BizException(_LicenseInfo.ValidateResult);
            }
        }

        /// <summary>
        /// 检查用户授权是否过期。
        /// </summary>
        /// <returns>true:软件已过期，false:没有过期</returns>
        /// <exception cref="BizException"></exception>
        public bool IsExpired()
        {
            this.LoadCache(true);

            _LicenseInfo = new UserLicenseInfo
            {
                IsExpired = false,
                ValidateResult = "软件使用正常，感谢您的支持！",
            };

            //获取电脑的mac地址
            var mac = NetTools.GetMacByNetworkInterface().Where(w => !string.IsNullOrEmpty(w))
                .Select(s => s.ToUpper()).Distinct().ToList();

            sys_ClientWhiteList row = null;

            //一台电脑有多个mac地址
            if (mac != null && mac.Count > 0)
            {
                row = _Cache.Where(w => mac.Contains(w.MAC) && w.FlagUse == "Y").FirstOrDefault();

                if (row == null)
                {
                    _LicenseInfo.IsExpired = true;
                    _LicenseInfo.ValidateResult = "您没有授权使用本软件，请联系供应商！";
                }
                else
                {
                    _LicenseInfo.IsExpired = row.ServerTime > row.ExpireTime;//判断软件过期：服务器日期>软件过期日期
                    _LicenseInfo.DaysRemaining = (row.ExpireTime.Value - row.ServerTime.Value).TotalDays;
                    _LicenseInfo.ExpireTime = row.ExpireTime.Value;
                    _LicenseInfo.ValidMacAddress = row.MAC;

                    if (_LicenseInfo.IsExpired)
                    {
                        _LicenseInfo.ValidateResult = "软件已过期，请联系供应商！";
                    }
                }
            }

            return _LicenseInfo.IsExpired;
        }

        /// <summary>
        /// 加载授权数据(mac+白名单)
        /// </summary>
        /// <param name="refreshData">是否刷新缓存数据</param>
        private void LoadCache(bool refreshData = true)
        {
            if (refreshData || _Cache == null || _Cache.Count == 0)
            {
                _Cache = new bllUser().GetClientWhitelist();

                //84-97-F6-89-E8-A0 => 去掉横杆
                _Cache.ForEach(i => i.MAC = i.MAC.Replace("-", "").Trim().ToUpper());
            }
        }

    }

        /// <summary>
        /// DAL层获取软件用户白名单列表
        /// </summary>
        /// <returns></returns>
        public List<sys_ClientWhiteList> GetClientWhitelist()
        {
            //仅获取启用的记录(FlagUse == "Y")
            var list = _Database.GetQueryable<sys_ClientWhiteList>().Where(w => w.FlagUse == "Y").ToList();
            var time = _Database.GetServerTime();
            list.ForEach(i => i.ServerTime = time);
            return list;
        }

    /// <summary>
    /// 用户软件授权提供者
    /// </summary>
    public static class UserLicenseProvider
    {
        static IUserLicenseProvider _Stratage = null;

        /// <summary>
        /// 用户授权校验策略，单例模式
        /// </summary>
        public static IUserLicenseProvider Current
        {
            get
            {
                if (_Stratage == null) _Stratage = new MacBlacklistProvider();

                return _Stratage;
            }
        }
    }

    if (BridgeFactory.InitializeBridge())//初始化后台数据连接
    {
        //检查软件授权
        UserLicenseProvider.Current.Check();

        //省略其他代码
    }