1 <configuration>
 2   <configSections>
 3     <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
 4   </configSections>
 5   <log4net>
 6     <!--定义输出到文件中-->
 7     <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
 8       <!--定义文件存放位置-->
 9       <file value="log\\"/>
10       <appendToFile value="true"/>
11       <rollingStyle value="Date"/>
12       <datePattern value="yyyy\\yyyyMM\\yyyyMMdd'.txt'"/>
13       <staticLogFileName value="false"/>
14       <param name="MaxSizeRollBackups" value="100"/>
15       <layout type="log4net.Layout.PatternLayout">
16         <!--每条日志末尾的文字说明-->
17         <!--输出格式-->
18         <!--样例：2008-03-26 13:42:32,111 [10] INFO  Log4NetDemo.MainClass [(null)] - info-->
19         <conversionPattern value="%newline %n记录时间：%date %n线程ID:[%thread] %n日志级别：  %-5level %n出错类：%logger property: [%property{NDC}] - %n错误描述：%message%newline %n"/>
20       </layout>
21     </appender>
22     <root>
23       <level value="ERROR"/>
24       <!--文件形式记录日志-->
25       <appender-ref ref="RollingLogFileAppender"/>
26     </root>
27   </log4net>
28 </configuration>

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5
 6 [assembly: log4net.Config.XmlConfigurator(Watch = true)]
 7 namespace TestLog4Net
 8 {
 9    public  class LogHelper
10     {
11         /// <summary>
12         /// 输出日志到Log4Net
13         /// </summary>
14         /// <param name="t"></param>
15         /// <param name="ex"></param>
16         #region static void WriteLog(Type t, Exception ex)
17         public static void WriteLog(Type t, Exception ex)
18         {
19             log4net.ILog log = log4net.LogManager.GetLogger(t);
20             log.Error("Error", ex);
21         }
22         #endregion
23
24         /// <summary>
25         /// 输出日志到Log4Net
26         /// </summary>
27         /// <param name="t"></param>
28         /// <param name="msg"></param>
29         #region static void WriteLog(Type t, string msg)
30         public static void WriteLog(Type t, string msg)
31         {
32             log4net.ILog log = log4net.LogManager.GetLogger(t);
33             log.Error(msg);
34         }
35         #endregion
36     }
37 }

// HOW TO USELogHelper.WriteLog(typeof(WebForm1), "test");