Question

How to (programmatically, without xml config) configure multiple loggers with Log4Net? I need them to write to different files.

Answer 1

This thread at the log4net Dashboard details an approach.

To summarize a little, hopefully without ripping off too much code:

using log4net; using log4net.Appender; using log4net.Layout; using log4net.Repository.Hierarchy;  // Set the level for a named logger public static void SetLevel(string loggerName, string levelName) {     ILog log = LogManager.GetLogger(loggerName);     Logger l = (Logger)log.Logger;      l.Level = l.Hierarchy.LevelMap[levelName];     }  // Add an appender to a logger public static void AddAppender(string loggerName, IAppender appender) {     ILog log = LogManager.GetLogger(loggerName);     Logger l = (Logger)log.Logger;      l.AddAppender(appender); }  // Create a new file appender public static IAppender CreateFileAppender(string name, string fileName) {     FileAppender appender = new         FileAppender();     appender.Name = name;     appender.File = fileName;     appender.AppendToFile = true;      PatternLayout layout = new PatternLayout();     layout.ConversionPattern = '%d [%t] %-5p %c [%x] - %m%n';     layout.ActivateOptions();      appender.Layout = layout;     appender.ActivateOptions();      return appender; }  // In order to set the level for a logger and add an appender reference you // can then use the following calls: SetLevel('Log4net.MainForm', 'ALL'); AddAppender('Log4net.MainForm', CreateFileAppender('appenderName', 'fileName.log'));  // repeat as desired