log4net and changing the logger levels

Recently I had the need to change the logging level for all loggers due to the need to hit the logging statements for NCover.  This was harder than it appeared, and I couldn’t really find anything out there that really documented the code you needed, so here’s the code:

private void TurnOnLogging() {
  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["DEBUG"];
    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["DEBUG"];
    }
  }

  // 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["DEBUG"];
}

Some caveat’s with this:

1. It’ll only work after you’ve already done something to cause the logging system to initialize.

2.  I’ll only see loggers that have been created.

Hopefully this is helpful to someone else!