Log4.net示例

//先用Nuget安装最新Log4net
using System;
using System.IO;
using log4net;
using log4net.Config;
using log4net.Repository;

namespace ConsoleApp
{
    public class Program
    {
        static void Main(string[] args) {

            ILoggerRepository repository = LogManager.CreateRepository("repository");

            //默认简单配置，输出到控制台
            //BasicConfigurator.Configure(repository);
            XmlConfigurator.Configure(repository, new FileInfo("log.config"));

            ILog log = LogManager.GetLogger(repository.Name, "log");
            log.Info("info");
            log.Error("error");

            Console.ReadLine();
        }
    }

}

log.config配置文件

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <!-- This section contains the log4net configuration settings -->
  <log4net>
    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
      <layout type="log4net.Layout.PatternLayout" value="%date [%thread] %-5level %logger - %message%newline" />
    </appender>

    <appender name="FileAppender" type="log4net.Appender.FileAppender">
      <file value="log-file.log" />
      <appendToFile value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
    </appender>

    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="logfile/" />
      <appendToFile value="true" />
      <rollingStyle value="Composite" />
      <staticLogFileName value="false" />
      <datePattern value="yyyyMMdd'.log'" />
      <maxSizeRollBackups value="10" />
      <maximumFileSize value="1MB" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%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="FileAppender" />
      <appender-ref ref="RollingLogFileAppender" />
    </root>

  </log4net>
</configuration>

引用地址 https://www.cnblogs.com/linezero/p/log4net.html