log4net fileappender not creating log-file.txt in Outlook ThisAddIn.cs

Question

I can't see what is wrong here. I just want to get log4net writing to a log file with my Outlook AddIn. I have the following in my app.config file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
     <configSections>
          <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,Log4net"/>
     </configSections>
<log4net>
     <appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender" >
         <param name="File" value="log-file.txt" />
         <param name="AppendToFile" value="true" />
         <rollingStyle value="Size" />
         <maxSizeRollBackups value="10" />
         <maximumFileSize value="10MB" />
         <staticLogFileName value="true" />
         <layout type="log4net.Layout.PatternLayout">
              <param name="ConversionPattern" value="%-5p%d{yyyy-MM-dd hh:mm:ss} – %m%n" />
         </layout>
     </appender>
     <root>
          <level value="DEBUG" />
          <appender-ref ref="LogFileAppender" />
     </root>
</log4net>
</configuration>

Here are the relevant statements in my startup class, ThisAddIn.cs (comments show variations I have tried):

//protected static readonly ILog log = LogManager.GetLogger("application-log");
public static readonly ILog log = LogManager.GetLogger(typeof(ThisAddIn));
private void ThisAddIn_Startup(object sender, System.EventArgs e)
{
    //BasicConfigurator.Configure();
    //XMLConfigurator.Configure();

    log.Info("Application Start");
    log.Warn("This is a warning message.");
    log.Debug("This is a debug message");

    if (log.IsDebugEnabled)
    {
        log.Debug("This is another debug message");
    }

In my research of this, it should write to a file called log-file.txt in my project/bin/Debug folder but I see nothing created. When I step into the code with the Debugger the methods of the log object appear to work without complaint. I also tried the following absolute specification for the file with the same lack of results:

<param name="File" value="c:\\try\\logger\\log-file.txt" />

Can someone spot my mistake?

Answer 1

Log4Net doesn't look in your app.config unless you tell him too. The log4net configuration you wrote in app.config could have also been written in a separate xml, or programatically in code.

You need to instruct log4net from where to take his configuration. See: http://logging.apache.org/log4net/release/manual/configuration.html

The easiest way to do it in your case is just add:

[assembly: log4net.Config.XmlConfigurator(Watch=true)]

anywhere in your Properties\AssemblyInfo.cs file.

After you do this: replace "c:\try\logger\log-file.txt" with only "log-file.txt" and after you run the program, you should then see in your Debug folder.