log4net simple configuration

app.config.xml

<configuration>

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

  <log4net>
    <!-- Define some output appenders -->
    <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="filename.log"/>
      <appendToFile value="true"/>
      <rollingStyle value="Size"/>
      <maxSizeRollBackups value="5"/>
      <maximumFileSize value="5MB"/>
      <staticLogFileName value="true"/>
      <filter type="log4net.Filter.LevelRangeFilter">
        <levelMin value="DEBUG" />
        <levelMax value="FATAL" />
      </filter>
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %level %logger - %message%newline"/>
      </layout>
    </appender>
    <!-- Setup the root category, add the appenders and set the default level -->
    <root>
      <level value="ALL"/>
      <appender-ref ref="RollingFileAppender"/>
    </root>
  </log4net>

</configuration>

log4net.use.cs

// using log4net.Config; no need for a reference -- fully qualified in the single instance, below

namespace MyNameSpace
{
    public class MyClass
    {
        // setup-info is in .config
        private static readonly log4net.ILog _log = log4net.LogManager.GetLogger
            (System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        public MyClass()
        {
            InitializeComponent();
            log4net.Config.XmlConfigurator.Configure();
            _log.Info("Class Initialized");
        }

    }
}