Question

I have the following file Log4net.config in my bin directory:

<?xml version="1.0" encoding="utf-8" ?>
<log4net xmlns="urn:log4net">
    <appender name="FileAppender" type="log4net.Appender.FileAppender">
        <param name="file" value="MyLogFile.log"/>
        <param name="appendToFile" value="false"/>
        <layout type="log4net.Layout.PatternLayout">
            <param name="ConversionPattern" value="%date (%logger) [%5level] - %message" />
        </layout>
    </appender>
    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
        <layout type="log4net.Layout.PatternLayout">
            <param name="ConversionPattern" value="%date (%logger) [%5level] - %message" />
        </layout>
    </appender>
    <root>
        <level value="DEBUG" />
        <appender-ref ref="FileAppender" />
        <appender-ref ref="ConsoleAppender"/>
    </root>
    <logger name="NHibernate" additivity="false">
        <level value="WARN"/>
    </logger>
</log4net>

And the following code in my AssemblyInfo.cs file:

using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

[assembly: AssemblyVersion("1.0.0.0")]
[assembly: AssemblyTitle("My Project")]
[assembly: log4net.Config.XmlConfigurator(ConfigFile = "Log4net.config", Watch = true)]

When I run the program, I get the following log4net debug output:

log4net: log4net assembly [log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=1b44e1d426115821]. Loaded from [D:\Data\Projects\Active\Clients\MyProject\src\MyProject.Importer\bin\Debug\log4net.dll]. (.NET Runtime [4.0.30319.1] on Microsoft Windows NT 6.1.7600.0)
log4net: DefaultRepositorySelector: defaultRepositoryType [log4net.Repository.Hierarchy.Hierarchy]
log4net: DefaultRepositorySelector: Creating repository for assembly [MyCompany.Framework, Version=2.1.72.0, Culture=neutral, PublicKeyToken=null]
log4net: DefaultRepositorySelector: Assembly [MyCompany.Framework, Version=2.1.72.0, Culture=neutral, PublicKeyToken=null] Loaded From [D:\Data\Projects\Active\Clients\MyProject\src\MyProject.Importer\bin\Debug\MyCompany.Framework.dll]
log4net: DefaultRepositorySelector: Assembly [MyCompany.Framework, Version=2.1.72.0, Culture=neutral, PublicKeyToken=null] does not have a RepositoryAttribute specified.
log4net: DefaultRepositorySelector: Assembly [MyCompany.Framework, Version=2.1.72.0, Culture=neutral, PublicKeyToken=null] using repository [log4net-default-repository] and repository type [log4net.Repository.Hierarchy.Hierarchy]
log4net: DefaultRepositorySelector: Creating repository [log4net-default-repository] using type [log4net.Repository.Hierarchy.Hierarchy]
The thread 'vshost.RunParkingWindow' (0xd30) has exited with code 0 (0x0).
The thread '<No Name>' (0x15d0) has exited with code 0 (0x0).
log4net: Hierarchy: Shutdown called on Hierarchy [log4net-default-repository]

Log4net loads, but doesn’t seem to be processing my config file. When I comment out the attribute in AssemblyInfo.cs and run the following code during my program initialization, it works as expected:

var log4netConfig = "Log4net.config";
var log4netInfo = new FileInfo(log4netConfig);
log4net.Config.XmlConfigurator.ConfigureAndWatch(log4netInfo);

What am I doing wrong? I want to load from AssemblyInfo.cs.

Answer 1

I also have trouble with this method of boostrapping log4net. The documentation says you have to make a call very early in your application startup

if you use configuration attributes you must invoke log4net to allow it to read the attributes. A simple call to LogManager.GetLogger will cause the attributes on the calling assembly to be read and processed. Therefore it is imperative to make a logging call as early as possible during the application start-up, and certainly before any external assemblies have been loaded and invoked.

Try placing a logger in the same class that starts your application (program.cs, app.xaml, whatever). For example

private static readonly ILog Log = LogManager.GetLogger(typeof(Program));

And for kicks, make any call to the log (even one that is filtered or evaluated out of the append process, it should force log4net to evaluate your repository/heirarchy).

static Program()
{
    Log.Debug("Application loaded.");
}