title: SqlXml removes XML header when comes from string
body: <p>I'm developing a web app with C# and MVC4. Currently I'm working in converting <strong>string vars to SqlXml files</strong>. I have a XML file with this structure:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;cfdi:Comprobante xsi:schemaLocation="http://www.sat.gob.mx/cfd/3 http://www.sat.gob.mx/sitio_internet/cfd/3/cfdv32.xsd http://www.sat.gob.mx/TimbreFiscalDigital http://www.sat.gob.mx/TimbreFiscalDigital/TimbreFiscalDigital.xsd" xmlns:tfd="http://www.sat.gob.mx/TimbreFiscalDigital" version="3.2" xmlns:cfdi="http://www.sat.gob.mx/cfd/3" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
  &lt;/cfdi:Comprobante&gt;
  </code></pre>
  
  <p>I'm converting the above file to string successfully and then I'm usign the following code that converts a string to a <strong>SqlXML</strong>.</p>
  
  <pre><code>cfdiDocumento.CFDIXML = Serializar.XMLToSqlXml(comprobante);
  </code></pre>
  
  <p>Where <strong>cfdiDocumento.CFDIXML</strong> is a <strong>SqlXml var</strong>,  <strong>Serializar.XMLToSqlXml(comprobante)</strong> method receives a string and executes the following code:</p>
  
  <pre><code>    public static SqlXml XMLToSqlXml(string xmlString)
      {
          SqlXml sqlXmlFiltro = null;
          if (xmlString != null)
          {
              StringReader sr = new StringReader(xmlString);
              XmlReaderSettings settings = new XmlReaderSettings();
              settings.ConformanceLevel = ConformanceLevel.Auto;
              XmlReader reader0 = XmlReader.Create(sr, settings);
              sqlXmlFiltro = new SqlXml(reader0);
          }
  
          return sqlXmlFiltro;
      }
  </code></pre>
  
  <p>When the code finishes successfully, the file is correct but is removing the <strong>xml header</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  </code></pre>
  
  <p>The question is: <strong>How do I preserve the xml header when convierting to SqlXml var?</strong></p>