1. .NET Core 控制台程序中使用

第一步：添加引用

Install-Package log4net

第二步：将附件 LogHelper.cs 和 log4net.config 两个文件加入到项目中

第三步：在Main中使用 LogHelper 类来记录日志

        public static void Main(string[] args)

        {

            LogHelper.Configure(); //使用前先配置

            LogHelper.Info("NETCorelog4net log");

            LogHelper.Info("test log");

            LogHelper.Error("error");

            LogHelper.Info("linezero");

            Console.ReadKey();

        }

2. ASP.NET Core 中使用

第一步：添加引用

Install-Package log4net

第二步：将附件 LogHelper.cs 和 log4net.config 两个文件加入到项目中

第三步：在Startup 构造函数中初始化

    public class Startup

    {

        public Startup()

        {

            LogHelper.Configure(); //使用前先配置

        }

第三步：在HomeController 中使用 LogHelper 类来记录日志

        public IActionResult Index()

        {

            LogHelper.Info("index view");

            LogHelper.Error("Controller Error");

            return View();

        }

附件

日志类简单封装：LogHelper.cs

    using log4net;

    using log4net.Config;

    using log4net.Repository;

    using System.IO;

    public class LogHelper

    {

        private static ILoggerRepository repository { get; set; }

        private static ILog _log;

        private static ILog log {

            get

            {

                if (_log == null)

                {

                    Configure();

                }

                return _log;

            }

        }

        public static void Configure(string repositoryName = "NETCoreRepository", string configFile = "log4net.config")

        {

            repository = LogManager.CreateRepository(repositoryName);

            XmlConfigurator.Configure(repository, new FileInfo(configFile));

            _log = LogManager.GetLogger(repositoryName, "");

        }

        public static void Info(string msg)

        {

            log.Info(msg);

        }

        public static void Warn(string msg)

        {

            log.Warn(msg);

        }

        public static void Error(string msg)

        {

            log.Error(msg);

        }

    }

log4net 配置文件：log4net.config 

<?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>