有引用log4net.dll

有配置文件，Web.config或log4net.config

有section节

<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
    <sectionGroup name="system.web">
        <section name="logService" type="OilDigital.CGGL.BLL.LogServiceSection, OilDigital.CGGL.BLL.Common" allowDefinition="MachineToApplication" restartOnExternalChanges="true"/>

有system.web节，同时确保logProviderWithLog4Net中的enabled为true

  <system.web>
    <logService defaultProvider="logProviderWithLog4Net">
      <providers>
        <add name="logProviderWithLog4Net" type="OilDigital.CGGL.BLL.Log.LogProviderWithLog4Net,OilDigital.CGGL.BLL.Log" enabled="true" loggingUserName="false" loggerName="OperationLogger"/>
      </providers>
    </logService>

有log4net节

<log4net>
    <appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="Logs\\opeartions-"/>
      <appendToFile value="true"/>
      <rollingStyle value="Date"/>
      <datePattern value="yyyy-MM-dd&quot;.log&quot;"/>
      <maximumFileSize value="10MB"/>
      <staticLogFileName value="false"/>
      <lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
      <layout type="log4net.Layout.PatternLayout">
        <param name="ConversionPattern" value="%d [%t] %-5p %c %m%n"/>
      </layout>
    </appender>
    <logger name="OperationLogger">
      <level value="INFO"/>
      <appender-ref ref="LogFileAppender"/>
    </logger>
  </log4net>

Global.asax的Application_Start方法中有初始化

            //初始化log4net对象
            log4net.Config.XmlConfigurator.Configure();