有時候，日志輸出的時候會根據時間來分類，譬如“20140821/trace.log”，在EnterPRise Library中通過工具配置，只能定義日志文件名稱，可以通過代碼修改FlatFileTraceListenerData實現或Custom Trace Listener方式，

通過代碼修改FlatFileTraceListenerData實現代碼如下：

        public static string GetTraceLogPath(string listenersName)        {            string _tracePath = string.Empty;            if (!string.IsNullOrEmpty(listenersName))            {                Configuration _etlConfig = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);                LoggingSettings _loggingSettings = (LoggingSettings)_etlConfig.GetSection(LoggingSettings.SectionName);                FlatFileTraceListenerData _listeners = _loggingSettings.TraceListeners.Get(listenersName) as FlatFileTraceListenerData;                if (_listeners != null)                {                    _tracePath = _listeners.FileName;                }            }            return _tracePath;        }        public static void SetTraceLogPath(string listenersName, string fileName)        {            if (!string.IsNullOrEmpty(listenersName) && !string.IsNullOrEmpty(fileName))            {                Configuration _etlConfig = ConfigurationManager.OpenExeConfiguration(System.Configuration.ConfigurationUserLevel.None);                LoggingSettings _loggingSettings = (LoggingSettings)_etlConfig.GetSection(LoggingSettings.SectionName);                FlatFileTraceListenerData _listeners = _loggingSettings.TraceListeners.Get(listenersName) as FlatFileTraceListenerData;                if (_listeners != null)                {                    _listeners.FileName = fileName;                    _etlConfig.Save();                }            }        }

測試代碼：

            try            {                string _listenName = "FlatFile TraceListener";                SetTraceLogPath(_listenName, string.Format(@"{0}/trace.log", DateTime.Now.ToString("yyyyMMdd")));                LogEntry log = new LogEntry();                log.Categories.Add("Warning");                log.Title = "測試";                log.Message = "日志日志內容";                Logger.Write(log);                LogEntry log2 = new LogEntry();                log2.Categories.Add("Warning");                log2.Title = "測試2";                log2.Message = "日志日志內容2";                Logger.Write(log2);                Console.WriteLine(GetTraceLogPath(_listenName));            }            catch (Exception ex)            {                Console.WriteLine(ex.Message);            }            finally            {                Console.ReadLine();            }

測試效果：

希望有所幫助