how-to set the log Level of log4net dynamically - console example with configuration

source:
log4net and changing the logger levels

//this is the xml added replace here your log4net and Nunit paths
//<Reference Include="log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=1b44e1d426115821, processorArchitecture=MSIL">
        //  <SpecificVersion>False</SpecificVersion>
        //  <HintPath>..\..\..\Log4Net\log4net-1.2.10\bin\net\2.0\release\log4net.dll</HintPath>
        //</Reference>
        //<Reference Include="nunit.framework, Version=2.4.8.0, Culture=neutral, PublicKeyToken=96d09a1eb7f44a77, processorArchitecture=MSIL" />

using System;
using System.Collections.Generic;
using System.Text;
using log4net;
using log4net.Config;
using NUnit.Framework;

namespace ExampleConsoleApplication
{
  enum DebugLevel : int
  { 
    Fatal_Msgs = 0 , 
    Fatal_Error_Msgs = 1 , 
    Fatal_Error_Warn_Msgs = 2 , 
    Fatal_Error_Warn_Info_Msgs = 3 ,
    Fatal_Error_Warn_Info_Debug_Msgs = 4 
  }
    

    class TestClass
    {

        private static readonly ILog logger =
                 LogManager.GetLogger ( typeof ( TestClass ) );


        static void Main ( string[] args )
        {
      TestClass objTestClass = new TestClass ();

            Console.WriteLine ( " START " );

      int shouldLog = 4; //CHANGE THIS FROM 0 TO 4 integer to check the functionality of the example
      //0 -- prints only FATAL messages 
      //1 -- prints FATAL and ERROR messages 
      //2 -- prints FATAL , ERROR and WARN messages 
      //3 -- prints FATAL  , ERROR , WARN and INFO messages 
      //4 -- prints FATAL  , ERROR , WARN , INFO and DEBUG messages 

      string srtLogLevel = String.Empty ; 
      switch (shouldLog)
      {
        case (int)DebugLevel.Fatal_Msgs :
          srtLogLevel = "FATAL";
          break;
        case (int)DebugLevel.Fatal_Error_Msgs:
          srtLogLevel = "ERROR";
          break;
        case (int)DebugLevel.Fatal_Error_Warn_Msgs :
          srtLogLevel = "WARN";
          break;
        case (int)DebugLevel.Fatal_Error_Warn_Info_Msgs :
          srtLogLevel = "INFO"; 
          break;
        case (int)DebugLevel.Fatal_Error_Warn_Info_Debug_Msgs :
          srtLogLevel = "DEBUG" ;
          break ;
        default:
          srtLogLevel = "FATAL";
          break;
      }

        objTestClass.SetLogingLevel ( srtLogLevel );
 

      objTestClass.LogSomething ();


            Console.WriteLine ( " END HIT A KEY TO EXIT " );
            Console.ReadLine ();
            } //eof method 

    /// <summary>
    /// Activates debug level 
    /// </summary>
    /// <sourceurl>http://geekswithblogs.net/rakker/archive/2007/08/22/114900.aspx</sourceurl>
    private void SetLogingLevel ( string strLogLevel )
    {
     string strChecker = "WARN_INFO_DEBUG_ERROR_FATAL" ;

      if (String.IsNullOrEmpty ( strLogLevel ) == true || strChecker.Contains ( strLogLevel ) == false)
        throw new Exception ( " The strLogLevel should be set to WARN , INFO , DEBUG ," );

      

      log4net.Repository.ILoggerRepository[] repositories = log4net.LogManager.GetAllRepositories ();

      //Configure all loggers to be at the debug level.
      foreach (log4net.Repository.ILoggerRepository repository in repositories)
      {
        repository.Threshold = repository.LevelMap[ strLogLevel ];
        log4net.Repository.Hierarchy.Hierarchy hier = (log4net.Repository.Hierarchy.Hierarchy)repository;
        log4net.Core.ILogger[] loggers = hier.GetCurrentLoggers ();
        foreach (log4net.Core.ILogger logger in loggers)
        {
          ( (log4net.Repository.Hierarchy.Logger)logger ).Level = hier.LevelMap[ strLogLevel ];
        }
      }

      //Configure the root logger.
      log4net.Repository.Hierarchy.Hierarchy h = (log4net.Repository.Hierarchy.Hierarchy)log4net.LogManager.GetRepository ();
      log4net.Repository.Hierarchy.Logger rootLogger = h.Root;
      rootLogger.Level = h.LevelMap[ strLogLevel ];
    }

    private void LogSomething ()
    {
      #region LoggerUsage
      DOMConfigurator.Configure (); //tis configures the logger 
      logger.Debug ( "Here is a debug log." );
      logger.Info ( "... and an Info log." );
      logger.Warn ( "... and a warning." );
      logger.Error ( "... and an error." );
      logger.Fatal ( "... and a fatal error." );
      #endregion LoggerUsage

    }
    } //eof class 

} //eof namespace 






#region TheAppConfig
/*
 <?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <section name="log4net"
                 type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
    </configSections>
    <log4net>
        <appender name="LogFileAppender" type="log4net.Appender.FileAppender">
            <param name="File" value="LogTest2.txt" />
            <param name="AppendToFile" value="true" />
            <layout type="log4net.Layout.PatternLayout">
                <param name="Header" value="[Header] \r\n" />
                <param name="Footer" value="[Footer] \r\n" />
                <param name="ConversionPattern" value="%d [%t] %-5p %c %m%n" />
            </layout>
        </appender>

        <appender name="ColoredConsoleAppender" type="log4net.Appender.ColoredConsoleAppender">
            <mapping>
                <level value="ERROR" />
                <foreColor value="White" />
                <backColor value="Red, HighIntensity" />
            </mapping>
            <layout type="log4net.Layout.PatternLayout">
                <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
            </layout>
        </appender>


        <appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
            <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=1.2.10.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <connectionString value="data source=ysg;initial catalog=DBGA_DEV;integrated security=true;persist security info=True;" />
            <commandText value="INSERT INTO [DBGA_DEV].[ga].[tb_Data_Log] ([Date],[Thread],[Level],[Logger],[Message]) VALUES (@log_date, @thread, @log_level, @logger, @message)" />
            
            <parameter>
                <parameterName value="@log_date" />
                <dbType value="DateTime" />
                <layout type="log4net.Layout.PatternLayout" value="%date{yyyy'-'MM'-'dd HH':'mm':'ss'.'fff}" />
            </parameter>
            <parameter>
                <parameterName value="@thread" />
                <dbType value="String" />
                <size value="255" />
                <layout type="log4net.Layout.PatternLayout" value="%thread" />
            </parameter>
            <parameter>
                <parameterName value="@log_level" />
                <dbType value="String" />
                <size value="50" />
                <layout type="log4net.Layout.PatternLayout" value="%level" />
            </parameter>
            <parameter>
                <parameterName value="@logger" />
                <dbType value="String" />
                <size value="255" />
                <layout type="log4net.Layout.PatternLayout" value="%logger" />
            </parameter>
            <parameter>
                <parameterName value="@message" />
                <dbType value="String" />
                <size value="4000" />
                <layout type="log4net.Layout.PatternLayout" value="%messag2e" />
            </parameter>
        </appender>
        <root>
            <level value="INFO" />
            <appender-ref ref="LogFileAppender" />
            <appender-ref ref="AdoNetAppender" />
            <appender-ref ref="ColoredConsoleAppender" />
        </root>
    </log4net>
</configuration>
 */
#endregion TheAppconfig