Question

I have a class

namespace LogToolsTest
{
    public class Foo
    {
        private static readonly ILog logger = LogManager.GetLogger(typeof(Foo));

        public Foo()
        {

            logger.Debug("Save this text");
            logger.Info("Save this text");
            logger.Warn("Save this text");
            logger.Error("Save this text");
            logger.Fatal("Save this text");


            var b1 = logger.IsDebugEnabled;
            var b2 = logger.IsInfoEnabled;
            var b3 = logger.IsWarnEnabled;
            var b4 = logger.IsErrorEnabled;
            var b5 = logger.IsFatalEnabled;
        }
    }
}

I test this by simple:

 Foo foo = new Foo();

and log4net.config

<?xml version="1.0" encoding="utf-8" ?>
<log4net>
  <root>
    <level value="DEBUG" />
    <appender-ref ref="EventLogAppender" />
  </root>

  <appender name="EventLogAppender" type="log4net.Appender.EventLogAppender" >
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
  </appender>


</log4net>

I added to my assemblyinfo:

[assembly: log4net.Config.XmlConfigurator(ConfigFile = 
"App.config", Watch = true)]

After execution of this code there is no entry in the event log. Why is that?

Now it’s working almost ok:
I deleted log4net.config, and modified my app.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <log4net>
  <root>
    <priority value="ALL" />
    <appender-ref ref="TraceAppender" />
    <appender-ref ref="ConsoleAppender" />
    <appender-ref ref="FileAppender" />
    <appender-ref ref="EventLogAppender" />
  </root>

  <appender name="TraceAppender" type="log4net.Appender.TraceAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
  </appender>

  <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
  </appender>

  <appender name="FileAppender" type="log4net.Appender.FileAppender">
    <file value="c:\\LOGS\\SampleLog.txt" />
    <appendToFile value="true" />
    <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
  </appender>
  <appender name="EventLogAppender" type="log4net.Appender.EventLogAppender" >
    <layout type="log4net.Layout.PatternLayout">
    </layout>
  </appender>
</log4net>
<configSections>
  <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
</configSections>

</configuration>

But something is wrong. I see in output:

System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: Unrecognized configuration section log4net. (C:\toolkit\trunk\LogToolsTest\bin\Debug\LogToolsTest.vshost.exe.config line 3)
   at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
   at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
   at System.Configuration.BaseConfigurationRecord.ThrowIfInitErrors()
   at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
   --- End of inner exception stack trace ---
   at System.Configuration.ConfigurationManager.PrepareConfigSystem()
   at System.Configuration.ConfigurationManager.GetSection(String sectionName)
   at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName)
   at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection()
   at System.Diagnostics.DiagnosticsConfiguration.Initialize()
   at System.Diagnostics.DiagnosticsConfiguration.get_IndentSize()
   at System.Diagnostics.TraceInternal.InitializeSettings()
   at System.Diagnostics.TraceInternal.WriteLine(String message)
   at System.Diagnostics.Trace.WriteLine(String message)
   at log4net.Util.LogLog.EmitErrorLine(String message)
log4net:ERROR DefaultRepositorySelector: Exception while reading ConfigurationSettings. Check your .config file is well formed XML.
System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: Unrecognized configuration section log4net. (C:\toolkit\trunk\LogToolsTest\bin\Debug\LogToolsTest.vshost.exe.config line 3)
   at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
   at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
   at System.Configuration.BaseConfigurationRecord.ThrowIfInitErrors()
   at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
   --- End of inner exception stack trace ---
   at System.Configuration.ConfigurationManager.PrepareConfigSystem()
   at System.Configuration.ConfigurationManager.GetSection(String sectionName)
   at System.Configuration.ConfigurationManager.get_AppSettings()
   at log4net.Util.SystemInfo.GetAppSetting(String key)

foreach appender.

Answer 1

I assume that you have a console program (it looks like you are testing log4net). So the first thing I would do is to make sure that logging works with more basic appenders. Configure a ConsoleAppender and make sure that you see the log statements. It is not strictly necessary to this, but as I said, that is what I would do.

The more important thing to do is to turn on internal debugging that should tell you why nothing is written to the event log.

Most likely you are facing a permission problem. Cf. log4net faq.