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。