AppSettings从数据库读取

    /// <summary>
    /// 提供对配置信息的访问
    /// </summary>
    public static class AppSettings
    {
        /// <summary>
        /// 配置信息
        /// </summary>
        private static volatile NameValueCollection _appSettingsCollection;

        /// <summary>
        /// 配置信息属性
        /// </summary>
        private static NameValueCollection AppSettingsCollection
        {
            get
            {
                return _appSettingsCollection ?? ReloadAppSettings();
            }
        }

        /// <summary>
        /// 重新加载配置信息
        /// </summary>
        /// <returns></returns>
        static NameValueCollection ReloadAppSettings()
        {
            var nameValueCollection = new NameValueCollection();
            //从数据库读取配置
                xxx.ToList()
                .ForEach(entity =>
                {
                    nameValueCollection[entity.Name] = entity.Value;
                });
            LastAppSettingsDateTime = DateTime.Now;
            _appSettingsCollection = nameValueCollection;
            return _appSettingsCollection;
        }

        /// <summary>
        /// 在启动时以后台任务刷新配置信息
        /// </summary>
        static AppSettings()
        {
            Task.Factory.StartNew(() =>
            {
                //按配置间隔分钟刷新配置信息
                for (; ; )
                {
                    try
                    {
                        //取配置的间隔分钟，默认为1分钟
                        double minutes;
                        if (_appSettingsCollection == null
                            || !double.TryParse(_appSettingsCollection["AppSettingsRefreshIntervalMinutes"], out minutes)
                            || minutes < 0.1)
                            minutes = 1D;

                        Task.Delay(TimeSpan.FromMinutes(minutes)).Wait();
                        ReloadAppSettings();
                    }
                    catch (Exception ex)
                    {
                    }
                }
            }, TaskCreationOptions.LongRunning);
        }

        /// <summary>
        /// 获取配置信息
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public static string Get(string name)
        {
            return AppSettingsCollection[name];
        }

        /// <summary>
        /// 最后获取配置信息的时间
        /// </summary>
        public static DateTime LastAppSettingsDateTime { get; private set; }
    }

遇到的问题：对于相同代码多处部署时，AppSettings配置的到处都是，略显冗余混乱。

解决办法：统一配置到数据库，方便修改。

效率考虑：增加一层静态缓存，采用定时刷新策略。