Implement this method to create your own layout format.
This method is called by an appender to format the loggingEvent as text and output to a writer.
If the caller does not have a TextWriter and prefers the event to be formatted as a String then the following code can be used to format the event into a StringWriter.
[C#]
StringWriter writer = new StringWriter();
Layout.Format(writer, loggingEvent);
string formattedEvent = writer.ToString();
ILayout Interface | log4net.Layout Namespace