很久之前研究微软的企业库时候写的，要注意需要引用Microsoft.Practices.EnterpriseLibrary.Logging组件库，因为ASP.NET5出来，微软在.netframework中自带了Logger，所以应该以后也不会用上。

using System;using System.Collections.Generic;using System.Diagnostics;using System.IO;using System.Linq;using System.Text;using Microsoft.Practices.EnterpriseLibrary.Logging;using Microsoft.Practices.EnterpriseLibrary.Logging.Formatters;using Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners;namespace Enuo.Core.Log{    /// 
    /// 标题：微软企业库日志模块调用类    /// 描述：目前适用Enterprise6.0    /// 作者：sunjipeng    /// 日期：2013-12-24    /// 
    public class EnterpriseLibraryLogger    {        #region Variables        static LogWriter logwriter;        static LoggingConfiguration config;        //static LogWriterFactory factory;        static string headerstyle = "------------Log--------------";        #endregion        #region Ctors        static EnterpriseLibraryLogger()        {            TextFormatter brie = new TextFormatter();            var flatFileTraceListener = new FlatFileTraceListener(DefaultDirectory, headerstyle, string.Empty, brie);            config = new LoggingConfiguration();            config.AddLogSource("mylog", SourceLevels.All, true).AddTraceListener(flatFileTraceListener);            logwriter = new LogWriter(config);        }        #endregion        #region Property Getter Setter        /// 
        /// 默认的日志路径        /// 
        public static string DefaultDirectory        {            get            {                string dirname = "AppLog";                string dir = Path.Combine(AppDomain.CurrentDomain.BaseDirectory,dirname);                if (!Directory.Exists(dir)) { Directory.CreateDirectory(dir); }                return dir;            }        }        #endregion        #region Public Methods        /// 
        /// 写入调试跟踪日志        /// 
        public static void WriteDebug(string msg)        {            if(logwriter.IsLoggingEnabled())            {                LogEntry entry = new LogEntry();                //事件号                entry.EventId = 9007;                entry.Message =  "日志信息";                //严重等级                entry.Priority = 9;                entry.Severity = TraceEventType.Verbose;                entry.Categories.Add("种类");                logwriter.Write(entry);            }         }        /// 
        /// 写入普通消息日志        /// 
        public void WriteInfo()        {            LogEntry entry = new LogEntry();            entry.Severity = TraceEventType.Information;            logwriter.Write(entry);        }        /// 
        /// 写入可恢复错误日志        /// 
        public void WriteError()        {            LogEntry entry = new LogEntry();            entry.Severity = TraceEventType.Error;            logwriter.Write(entry);        }        /// 
        /// 写入错误或应用程序崩溃日志        /// 
        public void WriteCritical()        {            LogEntry entry = new LogEntry();            entry.Severity = TraceEventType.Critical;            logwriter.Write(entry);        }        #endregion    }}