使用Nuget安装 log4net 创建一个log4net.config 文件 输入如下代码

   <?xml version="1.0" encoding="utf-8" ?><configuration>	<configSections>		<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />	</configSections>	<log4net>		<root>		</root>		<logger name="Error">			<level value="ALL" />			<appender-ref ref="ErrorAppender" />		</logger>		<logger name="InfoLog">			<level value="ALL" />			<appender-ref ref="InfoAppender" />		</logger>		<appender name="ErrorAppender" type="log4net.Appender.RollingFileAppender,log4net" >			<param name="File" type="" value="Log/Error/" />			<param name="AppendToFile" value="true" />			<param name="RollingStyle" value="Date" />			<param name="DatePattern" value="yyyyMMdd" />			<param name="StaticLogFileName" value="false" />			<layout type="log4net.Layout.PatternLayout,log4net">				<param name="ConversionPattern" value="%n[%d] %c %n%m%n%n" />				<param name="Header" value="-----------BEGIN-----------" />				<param name="Footer" value="------------END------------" />			</layout>		</appender>		<appender name="InfoAppender" type="log4net.Appender.RollingFileAppender,log4net" >			<param name="File" type="" value="Log/Info/" />			<param name="AppendToFile" value="true" />			<param name="RollingStyle" value="Date" />			<param name="DatePattern" value="yyyyMMdd" />			<param name="StaticLogFileName" value="false" />			<layout type="log4net.Layout.PatternLayout,log4net">				<param name="ConversionPattern" value="%n[%d] %c %n%m%n%n" />				<param name="Header" value="-----------BEGIN-----------" />				<param name="Footer" value="------------END------------" />			</layout>		</appender>	</log4net></configuration>

3.点击工程Properties->AssemblyInfo.cs 文件打开添加

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

4.创建类Log4netHelper

  public class Log4netHelper    {        /// <summary>        /// 普通日志        /// </summary>        /// <param name="message">日志内容</param>        public static void Info(string message)        {            log4net.ILog log = log4net.LogManager.GetLogger("InfoLog");            if (log.IsInfoEnabled)            {                log.Info(message);            }            log = null;        }        /// <summary>        /// 错误日志        /// </summary>        /// <param name="message">错误日志</param>        public static void Error(string message)        {            log4net.ILog log = log4net.LogManager.GetLogger("Error");            if (log.IsInfoEnabled)            {                log.Error(message);            }            log = null;        }        //        log4netHelper.Info("这是一条普通日志");        //log4netHelper.Error("这是一条错误日志");    }

5.使用时：

// log4netHelper.Info("这是一条普通日志");

//log4netHelper.Error("这是一条错误日志");

打开根目录能够看到一个log 文件夹。