title: the relative file path in asp.net's app_code
body: <p>In my asp.net application,I have a util class will read some data from a xml file,then I can call this class later,the file should loaded once,so I use the static constructor.</p>
  
  <pre><code>class UtilHelper{
    static UtilHelper(){
      XmlDocument doc=new XmlDocument();
      doc.load("a.xml"); //here the asp.net cannot find the file,it always try to find file in the iis's dictionary.
    }
  }
  </code></pre>
  
  <p>Some people may suggest I use the "Server.mappath(xxx)"</p>
  
  <p>But this class is not the xx.aspx.cs. So there is no "HttpRequest" or "HttpServerUtilly" in the context.</p>
  
  <p>Any ideas?</p>