Private Shared ReadOnly log As ILog = LogManager.GetLogger("")

我试图用以下方式使用它：

If log.IsDebugEnabled Then
   log.Debug("Integration Services Constructed")
End If

这是我的配置：

<log4net>

    <root>
        <level value="DEBUG" />
        <appender-ref ref="RollingFileAppender" />
    </root>

    <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
        <file value="..\\logs\\logfile.log"/>
        <appendToFile value="true"/>
        <rollingStyle value="Size"/>
        <maxSizeRollBackups value="10"/>
        <maximumFileSize value="1MB"/>
        <staticLogFileName value="true"/>
        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline"/>
        </layout>
        <filter type="log4net.Filter.LevelRangeFilter">
            <param name="LevelMin" value="DEBUG" />
            <param name="LevelMax" value="FATAL" />
        </filter>
    </appender>

</log4net>

不幸的是，log.IsDebugEnabled始终为false。如何配置log4net，以便我只能记录调试消息？