Change log4net logging level programmatically

Ken picture Ken · Apr 4, 2009 · Viewed 45.8k times · Source

This is similar to 650694 but no answer was accepted there, I can't get any of those suggestions to work at all, and I suspect I may be in a slightly different situation.

I'm calling log4net.Config.XmlConfigurator.Configure(). But after that point in the program, I want to change the logging threshold to a value only known at runtime.

From the other question, I tried:

((log4net.Repository.Hierarchy.Logger)mylogger.Logger).Level = log4net.Core.Level.Error;

and:

var appender = new log4net.Appender.ColoredConsoleAppender();
appender.Layout = new log4net.Layout.PatternLayout(@"%date %-5level %message%newline");
appender.Threshold = log4net.Core.Level.Error;
appender.ActivateOptions();
log4net.Config.BasicConfigurator.Configure(appender);

but neither one seems to have any effect: I'm still seeing DEBUG and INFO logging statements on the console.

My hunch is that I'm adding a new appender, which has no effect on the appender declared in the XML config (which tells it to print DEBUG level messages), but I don't have any evidence for this yet.

I've been digging through the log4net API for a while now, and I'm just not seeing it. Is there something simple I'm missing?

Answer

JeanT picture JeanT · Dec 28, 2011

None of these solutions present here worked for me. It wasn't changing at runtime

Here is what worked for me:

((log4net.Repository.Hierarchy.Hierarchy)LogManager.GetRepository()).Root.Level = Level.Debug;
((log4net.Repository.Hierarchy.Hierarchy)LogManager.GetRepository()).RaiseConfigurationChanged(EventArgs.Empty);

You have to call RaiseConfigurationChanged after making changes to its config.