title: Trying to parse xml, but xmldocument.loadxml() is trying to download?
body: <p>I have a string input that i do not know whether or not is valid xml.</p>
  
  <p>I think the simplest aprroach is to wrap </p>
  
  <pre><code>new XmlDocument().LoadXml(strINPUT);
  </code></pre>
  
  <p>In a try/catch.</p>
  
  <p>The problem im facing is, sometimes <code>strINPUT</code> is an html file, if the header of this file contains </p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC ""-//W3C//DTD XHTML 1.0 Transitional//EN"" ""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd""&gt;
  &lt;html xml:lang=""en-GB"" xmlns=""http://www.w3.org/1999/xhtml"" lang=""en-GB""&gt;
  </code></pre>
  
  <p>...like many do, it actually tries to make a connection to the w3.org url, which i really dont want it doing.</p>
  
  <p>Anyone know if its possible to just parse the string without trying to be clever and checking external urls? Failing that is there an alternative to <code>xmldocument</code>?</p>