title: How do I use a GlobalContext property in a log4net appender name?
body: <p>I'm trying to customise a log4net file path to use a property I have set in the <code>log4net.GlobalContext.Properties</code> dictionary.</p>
  
  <pre><code>log4net.GlobalContext.Properties["LogPathModifier"] = "SomeValue";
  </code></pre>
  
  <p>I can see that this value is set correctly when debugging through it. and then in my configuration</p>
  
  <pre><code>&lt;file type="log4net.Util.PatternString" 
        value="Logs\%appdomain_%property{LogPathModifier}.log" /&gt;
  </code></pre>
  
  <p>However, the output of this gives me "_(null).log" at the end of the path. What gives?</p>