log4net 使用步骤

1.安装log4net 

　　官网首页：http://logging.apache.org/log4net/

　　下载地址：http://logging.apache.org/log4net/download_log4net.cgi

　　找到对应.net版本的 log4net.dll

　　在项目中引用 下载的 log4net.dll 

3.书写配置文件：

　　log4net可以将日志写到控制台，文本文件，数据库（access，MS SQL,mysql，oracle,SQLite  等...）所以需要填写配置文件

　　配置文件的写法：http://logging.apache.org/log4net/release/config-examples.html

　　第一步：添加节点  在configSections添加 section log4net

<configSections>
        <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>

　　第二步：在configuration节点下添加<log4net>

<log4net>
        <!-- Console部分log输出格式的设定 -->
        <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
            <layout type="log4net.Layout.PatternLayout">
                <conversionPattern value="%date [%thread] %-5level %logger %ndc - %message%newline" />
            </layout>
        </appender>
        <!-- 日志文件部分log输出格式的设定 -->
        <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
            <file value="log\\" />
            <appendToFile value="true" />
            <maxSizeRollBackups value="10" />
            <maximumFileSize value="10MB" />
            <rollingStyle value="Size" />
            <staticLogFileName value="true" />
            <layout type="log4net.Layout.PatternLayout">
                <header value="[Header] " />
                <footer value="[Footer] " />
                <ConversionPattern value="%date [%thread] %-5level - %message%newline%newline" />
            </layout>
        </appender>
        <!-- Setup the root category, add the appenders and set the default level -->
        <root>
            <level value="ALL" />
            <appender-ref ref="ConsoleAppender" />
            <appender-ref ref="RollingLogFileAppender" />
        </root>
    </log4net>

　　完整的APP.config 如下：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
        <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
    </configSections>
    <startup>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
    </startup>
    <log4net>
        <!-- Console部分log输出格式的设定 -->
        <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
            <layout type="log4net.Layout.PatternLayout">
                <conversionPattern value="%date [%thread] %-5level %logger %ndc - %message%newline" />
            </layout>
        </appender>
        <!-- 日志文件部分log输出格式的设定 -->
        <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
            <file value="log\\" />
            <appendToFile value="true" />
            <maxSizeRollBackups value="10" />
            <maximumFileSize value="10MB" />
            <rollingStyle value="Size" />
            <staticLogFileName value="true" />
            <layout type="log4net.Layout.PatternLayout">
                <header value="[Header] " />
                <footer value="[Footer] " />
                <ConversionPattern value="%date [%thread] %-5level - %message%newline%newline" />
            </layout>
        </appender>
        <!-- Setup the root category, add the appenders and set the default level -->
        <root>
            <level value="ALL" />
            <appender-ref ref="ConsoleAppender" />
            <appender-ref ref="RollingLogFileAppender" />
        </root>
    </log4net>
    <appSettings>
        <add key="RegistrationCode" value=""/>
    </appSettings>
</configuration>

4.添加一个LogHelper类，以便随时静态调用　　

using System;
using System.Reflection;
using log4net;

namespace Text2Excel.Helper
{
  public static class LogHelper
    {
      private static readonly ILog mLog = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
      public static void WriteLog(string date, Exception e)
      {
          mLog.Error(date + ":" + e.Message + "\r\n" + e.StackTrace);
      }
      public static void WriteLog(Exception ex)
      {
          mLog.Error(ex.Message + "\r\n" + ex.StackTrace);
      }

      public static void WriteLog(string msg)
      {
          mLog.Error(msg);
      }
      //TODO: 扩展自己想用的方法
    }
}