1.install-package log4net

2.add new config file, its name is log4net.config

3.Right click the log4net.config and set Copy to Output Directory as 'Copy Always'

4.Open AssemblyInfo.cs and append to the end

[assembly:log4net.Config.XmlConfigurator(ConfigFile ="log4net.config")]

5. 

 private static readonly log4net.ILog logger = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);        static void Main(string[] args)
        {
            Log4netDemo();
            Console.ReadLine();
        }        static void Log4netDemo()
        {           
            logger.Info($"{DateTime.Now.ToString("yyyyMMddHHmmssffff")}");            
            logger.Error($"{DateTime.Now.ToString("yyyyMMddHHmmssffff")}");
            logger.Debug($"{DateTime.Now.ToString("yyyyMMddHHmmssffff")}");
            logger.Fatal($"{DateTime.Now.ToString("yyyyMMddHHmmssffff")}");
            logger.Warn($"{DateTime.Now.ToString("yyyyMMddHHmmssffff")}");             
        }

C# log4net_C# log4net

 

Of course,you can set the file location manually as below

or

<appender name="file" type="log4net.Appender.RollingFileAppender">     
      <file type="log4net.Util.PatternString" value="Logs\\Common\\%date{yyyy-MM-dd-HH-mm-ss-ffff}.log" />
      <appendToFile value="true" />
      <rollingStyle value="Size" />
      <maxSizeRollBackups value="5" />
      <maximumFileSize value="10MB" />
      <staticLogFileName value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %level %logger - %message%newline" />
      layout>
    appender>