Writing an Appender for log4net

The open source logging library log4net ships with most of the appenders you will ever need, but if you need to write your own, it is surprisingly easy to do. This article describes how to write a simple appender that allows you to show a message box whenever an error log occurs and allows the developer to break into the debugger to fix the error. It makes sure that runtime errors are dealt with by the developer, not lost in a log file. This example could easily be extended to do things like open issues in a bug tracking system on errors.