<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <log4net>
    <appender name="MyAppender1" type="log4net.Appender.RollingFileAppender">
      <file value="app.log" />  <!--日志文件名-->
      <appendToFile value="true" /> <!--日志文件以追加方式進(jìn)行-->
      <rollingStyle value="Size" />   <!--按文件大小進(jìn)行滾動(dòng)記錄，也可以按日期-->
      <maxSizeRollBackups value="2" />  <!--最多兩個(gè)日志備份，app.log.1 app.log.2-->
      <maximumFileSize value="8KB" /> <!--日志文件達(dá)到8KB就重新記一個(gè)文件-->
      <staticLogFileName value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <!--每一行日志輸出格式-->
        <conversionPattern value="%date [%thread] (%file:%line) %-5level %logger - %message%newline" />
      </layout>
    </appender>
 
    <logger name="Mylog1">  <!--代碼通過(guò)Mylog1獲取對(duì)應(yīng)的logger句柄-->
        <level value="WARN" /> <!--比WARN等級(jí)低的不會(huì)輸出 日志等級(jí)由高到低:OFF > FATAL > ERROR > WARN > INFO > DEBUG > ALL-->
        <appender-ref ref="MyAppender1" /> <!--啟用MyAppender1-->
    </logger>
  </log4net>
</configuration>

namespace Log4netTest
{
    public partial class Form1 : Form
    {
        //Mylog1對(duì)應(yīng)log.config種的一個(gè)logger名稱
        public static readonly log4net.ILog mLogger = log4net.LogManager.GetLogger("Mylog1");
 
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
            mLogger.Error("APP Start");
            mLogger.Debug("logDebug");
            mLogger.Info("logInfo");
            mLogger.Warn("logWarn");
            mLogger.Error("logError");
            mLogger.Error(this);
        }
    }