Log4net xml output

As suggested by MrPeregrination you need to write a class deriving from XmlLayoutBase, override the FormatXml method and instruct your appender to use it as layout:

class Program{    static void Main(string[] args)    {        XmlConfigurator.Configure();        ILog log = log4net.LogManager.GetLogger(typeof(Program));        log.Debug("Hello world");    }}public class MyXmlLayout : XmlLayoutBase{    protected override void FormatXml(XmlWriter writer, LoggingEvent loggingEvent)    {        writer.WriteStartElement("LogEntry");        writer.WriteStartElement("Message");        writer.WriteString(loggingEvent.RenderedMessage);        writer.WriteEndElement();        writer.WriteEndElement();    }}

And in app.config put this:

<?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.txt" />      <param name="AppendToFile" value="true" />      <rollingStyle value="Size" />      <maxSizeRollBackups value="10" />      <maximumFileSize value="10MB" />      <staticLogFileName value="true" />      <layout type="MyNamespace.MyXmlLayout" />    </appender>    <root>      <level value="DEBUG" />      <appender-ref ref="LogFileAppender" />    </root>  </log4net></configuration>

This will produce entries like this in your log file:

<LogEntry><Message>Hello world</Message></LogEntry>

Adding to Darin's answer, in log4net 2.0.8, I had to change the layout a little:

<layout type="MyNamespace.MyClass, MyNamespace"/>

I found this here http://www.codewrecks.com/blog/index.php/2008/04/29/writing-a-custom-formatter-for-log4net/

Check out the XmlLayoutBase class. I think thats probably what you need. There's a FormatXML function you will need to override to supply the XmlWriter with the correctly formatted data.