log4net不同logger输出日志

4步曲

1.引用log4net.dll（nuget）

2.任意位置的命名空间头部加入下面的代码，web.config可修改为自己定义的.xml

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

3.web.config -> <configuration>/<configSections>配置

<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />

4.web.config -> <configuration>配置

   <log4net>
     <logger name="[one_name]">
       <level value="Info"/>
       <appender-ref ref="[two_name]" />
     </logger>
     <appender name="[two_name]" type="log4net.Appender.RollingFileAppender">
       <param name="File" type="log4net.Util.PatternString" value="log4net\[one_name]\%date{yyyy}\%date{yyyyMM}\%date{yyyyMMdd}.log" />
       <param name="Encoding" value="UTF-8" />
       <param name="AppendToFile" value="true" />
       <param name="MaxSizeRollBackups" value="10" />
       <datePattern value="yyyy-MM-dd&quot;-Debug.log&quot;" />
       <param name="MaximumFileSize" value="2MB" />
       <param name="RollingStyle" value="Size" />
       <param name="StaticLogFileName" value="false" />
       <layout type="log4net.Layout.PatternLayout">
         <param name="ConversionPattern" value="%date [%thread] %logger %-5level - %message%newline" />
       </layout>
     </appender>
     <root>
       <level value="ALL" />
       <appender-ref ref="RollingFileAppender" />
     </root>
   </log4net>

注意点

1.括号里面的two_name必须一致，很重要

2.<logger>标签可使log4net定义输出无数个独立的日志文件

3.%date{yyyyMMddHHmmssff}=年月日时分秒毫秒，%date{}不能少