无论设置了哪个级别，如何将行写到log4net日志文件？

Question

How do I write an entry to a log4net file regardless which log level is set at that moment? The only way I can assure a line will be added, is to add a 'Fatal' entry. And that is ugly and will even fail if the level is set to 'Off'.

For instance: I want to log that the log level was changed to 'Error'. If I would use:

Logger.Log.Info($"LogLevel set to {logLevelText}");

Then this line will not be written if the level was just set to 'Error'.

So, is there a way to just write a line to the log?

Answer 1

Nope. You cannot write an entry, without a log level. You can however manipulate log levels at runtime. So you can set the log level momentarily to whatever you need, just to ensure your message is written to the log, then restore the original level. See this SO thread for details.

Answer 2

This is how I'm using it in my project. Hope it help.

private static readonly log4net.ILog rootlog = log4net.LogManager.GetLogger("rootLogger");

rootlog.Info(string.Format("Service [{0}] has started.", this.ServiceName)); // info msg

rootlog.Error(string.Format("Get Tasks Unsuccessfull: {0}", response.MessageValue)); // error msg