Changing the log level programmatically in log4net?

Question

Is there a way to set the log level in log4net programmatically? I\'d assumed that there would be a property that would let you do this, but I can\'t seem to find one.

Answer 1

You could download the sample project from here or copy paste the code bellow. At the end of the code is the DDL SQL for the table holding the logging info ..

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

  namespace ExampleConsoleApplication
  {


    class TestClass
    {

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


        static void Main ( string[] args )
        {
        TestClass objTestClass = new TestClass ();
  //log4net.Appender.ColoredConsoleAppender.Colors.HighIntensity
        GenApp.Bo.UserSettings us = new GenApp.Bo.UserSettings ();
        GenApp.Bo.User userObj = new GenApp.Bo.User ()
        {

          UserSettings = us

        };
        userObj.UserSettings.LogLevel = 4; 




        #region SetDynamicallyLogLevel


        Logger.Debug ( userObj, logger, " -- Debug msg -- " );
        Logger.Info ( userObj, logger, " -- Info msg -- " );
        Logger.Warn ( userObj, logger, " -- Warn msg -- " );
        Logger.Error ( userObj, logger, " -- Error msg -- " );
        Logger.Fatal ( userObj, logger, " -- Fatal msg -- " );
        #endregion SetDynamicallyLogLevel



        #region RemoveDynamicallyAppenders
        Logger.SetThreshold ( "LogFileAppender", log4net.Core.Level.Off );

        //and echo again
        Logger.Debug ( userObj, logger, " -- Debug msg -- " );
        Logger.Info ( userObj, logger, " -- Info msg -- " );
        Logger.Warn ( userObj, logger, " -- Warn msg -- " );
        Logger.Error ( userObj, logger, " -- Error msg -- " );
        Logger.Fatal ( userObj, logger, " -- Fatal msg -- " );



        #endregion RemoveDynamicallyAppenders

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


    } //eof class 

  } //eof namespace 




  /* App.config CopyPaste 
  


  




  
    
    
    
      
      
    
  

  
    
      
      
    
    
      
      
    
    
      
      
    
    
      
      
    
    
      
      
      
    

    
      
      
    
  


  
    
    
    

    
      
      
      
    
    
      
      
      
      
    
    
      
      
      
      
    
    
      
      
      
      
    
    
      
      
      
      
    
    
      
      
      
      
    
  
  
    
    
    
    
  


   */
  #region TheReferencesInThecsprojFile
  //
  //  False
  //  ..\..\..\Log4Net\log4net-1.2.10\bin\net\2.0\release\log4net.dll
  //
  //
  #endregion TheReferencesInThecsprojFile


namespace GenApp.Bo
{
  public class User
  {

    public int LogLevel { get; set; }
    public UserSettings UserSettings { get; set; }


  } //eof class 

  public class UserSettings
  {
    public int LogLevel;
  }

} //eof namespace 

namespace GenApp.Utils
{
  /// 1.1 
  /// Yordan Georgiev 
  ///
 Wrapper around log4net with dynamically adjustable verbosity
  public class Logger
  {

    private static Logger inst = new Logger ();
    public static Logger Inst ()
    {
      inst.ConfigureLogging ();
      return inst;
    }


    public 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
    }

    public static void Debug ( GenApp.Bo.User userObj, ILog logger, string msg )
    {
      DebugLevel debugLevel = (DebugLevel)userObj.UserSettings.LogLevel;
      string strLogLevel = Logger.GetLogTypeString ( debugLevel );
      inst.SetLogingLevel ( strLogLevel );
      logger.Debug ( msg );

    } //eof method 


    public static void Info ( GenApp.Bo.User userObj, ILog logger, string msg )
    {
      DebugLevel debugLevel = (DebugLevel)userObj.UserSettings.LogLevel;
      string strLogLevel = Logger.GetLogTypeString ( debugLevel );
      inst.SetLogingLevel ( strLogLevel );
      logger.Info ( msg );

    } //eof method 


    public static void Warn ( GenApp.Bo.User userObj, ILog logger, string msg )
    {
      DebugLevel debugLevel = (DebugLevel)userObj.UserSettings.LogLevel;
      string strLogLevel = Logger.GetLogTypeString ( debugLevel );
      inst.SetLogingLevel ( strLogLevel );
      logger.Warn ( msg );

    } //eof method 


    public static void Error ( GenApp.Bo.User userObj, ILog logger, string msg )
    {
      DebugLevel debugLevel = (DebugLevel)userObj.UserSettings.LogLevel;
      string strLogLevel = Logger.GetLogTypeString ( debugLevel );
      inst.SetLogingLevel ( strLogLevel );
      logger.Error ( msg );
    } //eof method 


    public static void Fatal ( GenApp.Bo.User userObj, ILog logger, string msg )
    {
      DebugLevel debugLevel = (DebugLevel)userObj.UserSettings.LogLevel;
      string strLogLevel = Logger.GetLogTypeString ( debugLevel );
      inst.SetLogingLevel ( strLogLevel );
      logger.Fatal ( msg );
    } //eof method 


    /// 

    /// Activates debug level 
    /// 
    /// http://geekswithblogs.net/rakker/archive/2007/08/22/114900.aspx
    private void SetLogingLevel ( string strLogLevel )
    {

      this.ConfigureLogging ();
      string strChecker = "WARN_INFO_DEBUG_ERROR_FATAL";

      if (String.IsNullOrEmpty ( strLogLevel ) == true || strChecker.Contains ( strLogLevel ) == false)
        throw new ArgumentOutOfRangeException ( " 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];
    }

    ///

    ///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 
    ///
    private static string GetLogTypeString ( DebugLevel debugLevel )
    {

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

    } //eof GetLogTypeString


    /// 

    /// The path where the configuration is read from.
    /// This value is set upon a call to ConfigureLogging().
    /// 
    private string configurationFilePath;
    public void ConfigureLogging ()
    {
      lock (this)
      {
        bool configured = false;


        #region ConfigureByThePathOfTheEntryAssembly
        // Tells the logging system the correct path.
        Assembly a = Assembly.GetEntryAssembly ();

        if (a != null && a.Location != null)
        {
          string path = a.Location + ".config";

          if (File.Exists ( path ))
          {
            log4net.Config.DOMConfigurator.Configure (
              new FileInfo ( path ) );
            configurationFilePath = path;
            configured = true;
          }
          else
          {
            path = FindConfigInPath ( Path.GetDirectoryName ( a.Location ) );
            if (File.Exists ( path ))
            {
              log4net.Config.DOMConfigurator.Configure (
                new FileInfo ( path ) );
              configurationFilePath = path;
              configured = true;
            }
          }
        }
        #endregion ConfigureByThePathOfTheEntryAssembly


        #region ConfigureByWeb.config
        //// Also, try web.config.
        //if (!configured)
        //{
        //  if (HttpContext.Current != null &&
        //    HttpContext.Current.Server != null &&
        //    HttpContext.Current.Request != null)
        //  {
        //    string path = HttpContext.Current.Server.MapPath (
        //      HttpContext.Current.Request.ApplicationPath );

        //    path = path.TrimEnd ( '\\' ) + "\\Web.config";

        //    if (File.Exists ( path ))
        //    {
        //      log4net.Config.DOMConfigurator.Configure (
        //        new FileInfo ( path ) );
        //      configurationFilePath = path;
        //      configured = true;
        //    }
        //  }
        //}
        #endregion ConfigureByWeb.config


        #region ConfigureByThePathOfTheExecutingAssembly
        if (!configured)
        {
          // Tells the logging system the correct path.
          a = Assembly.GetExecutingAssembly ();

          if (a != null && a.Location != null)
          {
            string path = a.Location + ".config";

            if (File.Exists ( path ))
            {
              log4net.Config.DOMConfigurator.Configure (
                new FileInfo ( path ) );
              configurationFilePath = path;
              configured = true;
            }
            else
            {
              path = FindConfigInPath ( Path.GetDirectoryName ( a.Location ) );
              if (File.Exists ( path ))
              {
                log4net.Config.DOMConfigurator.Configure (
                  new FileInfo ( path ) );
                configurationFilePath = path;
                configured = true;
              }
            }
          }
        }
        #endregion ConfigureByThePathOfTheExecutingAssembly


        #region ConfigureByThePathOfTheCallingAssembly
        if (!configured)
        {
          // Tells the logging system the correct path.
          a = Assembly.GetCallingAssembly ();

          if (a != null && a.Location != null)
          {
            string path = a.Location + ".config";

            if (File.Exists ( path ))
            {
              log4net.Config.DOMConfigurator.Configure (
                new FileInfo ( path ) );
              configurationFilePath = path;
              configured = true;
            }
            else
            {
              path = FindConfigInPath ( Path.GetDirectoryName ( a.Location ) );
              if (File.Exists ( path ))
              {
                log4net.Config.DOMConfigurator.Configure (
                  new FileInfo ( path ) );
                configurationFilePath = path;
                configured = true;
              }
            }
          }
        }
        #endregion ConfigureByThePathOfTheCallingAssembly


        #region ConfigureByThePathOfTheLibIsStored
        if (!configured)
        {
          // Look in the path where this library is stored.
          a = Assembly.GetAssembly ( typeof ( Logger ) );

          if (a != null && a.Location != null)
          {
            string path = FindConfigInPath ( Path.GetDirectoryName ( a.Location ) );
            if (File.Exists ( path ))
            {
              log4net.Config.DOMConfigurator.Configure (
                new FileInfo ( path ) );
              configurationFilePath = path;
              configured = true;
            }
          }
        }
        #endregion ConfigureByThePathOfTheLibIsStored



      } //eof lock   
    } //eof method 



    /// 

    /// Searches for a configuration file in the given path.
    /// 
    private string FindConfigInPath (
      string path )
    {
      string[] files = Directory.GetFiles ( path );

      if (files != null && files.Length > 0)
      {
        foreach (string file in files)
        {
          if (Path.GetExtension ( file ).Trim ( '.' ).ToLower (
            CultureInfo.CurrentCulture ) == "config")
          {
            return file;
          }
        }
      }

      // Not found.
      return string.Empty;
    } //eof method 



    /// 

    /// Remove dynamically appenders
    /// 
    /// 
    /// 
    public static void SetThreshold ( string appenderName, Level threshold )
    {
      foreach (AppenderSkeleton appender in LogManager.GetRepository ().GetAppenders ())
      {
        if (appender.Name == appenderName)
        {
          appender.Threshold = threshold;
          appender.ActivateOptions ();

          break;
        }
      }
    } //eof method 



  } //eof class 


} //eof namespace 

USE [DBGA_DEV]
GO

/****** Object:  Table [ga].[tb_Data_Log]    Script Date: 05/20/2009 12:16:01 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

SET ANSI_PADDING ON
GO

CREATE TABLE [ga].[tb_Data_Log](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [Date] [datetime] NOT NULL,
    [Thread] [varchar](255) NOT NULL,
    [Level] [varchar](20) NOT NULL,
    [Logger] [varchar](255) NOT NULL,
    [Message] [varchar](4000) NOT NULL
) ON [PRIMARY]

GO

SET ANSI_PADDING ON
GO