private readonly ILogger<fluueController> _logger;    
      
public fluueController(ILogger<fluueController> logger){

_logger =logger;

}

引入命名空间：using Microsoft.Extensions.Logging;

<log4net>

  <!-- Define some output appenders -->

  <appender name="rollingAppender" type="log4net.Appender.RollingFileAppender">

    <file value="log\log.txt" />

 

    <!--追加日志内容-->

    <appendToFile value="true" />

 

    <!--防止多线程时不能写Log,官方说线程非安全-->

    <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />

 

    <!--可以为:Once|Size|Date|Composite-->

    <!--Composite为Size和Date的组合-->

    <rollingStyle value="Composite" />

 

    <!--当备份文件时,为文件名加的后缀-->

    <datePattern value="yyyyMMdd.TXT" />

 

    <!--日志最大个数,都是最新的-->

    <!--rollingStyle节点为Size时,只能有value个日志-->

    <!--rollingStyle节点为Composite时,每天有value个日志-->

    <maxSizeRollBackups value="20" />

 

    <!--可用的单位:KB|MB|GB-->

    <maximumFileSize value="3MB" />

 

    <!--置为true,当前最新日志文件名永远为file节中的名字-->

    <staticLogFileName value="true" />

 

    <!--输出级别在INFO和ERROR之间的日志-->

    <filter type="log4net.Filter.LevelRangeFilter">

      <param name="LevelMin" value="INFO" />

      <param name="LevelMax" value="FATAL" />

    </filter>

 

    <layout type="log4net.Layout.PatternLayout">

      <conversionPattern value="%date [%thread] %-5level %logger - %message%newline"/>

    </layout>

  </appender>

 

  <!-- levels: OFF > FATAL > ERROR > WARN > INFO > DEBUG  > ALL -->

  <root>

    <priority value="ALL"/>

    <level value="ALL"/>

    <appender-ref ref="rollingAppender" />

  </root>

</log4net>

Host.CreateDefaultBuilder(args).ConfigureLogging(ILoggingBuilder=> {ILoggingBuilder.AddLog4Net();})