Question

I what to retrieve a string representation of the xml fragment for the HB_Base element. Could anyone point it out the best way.

<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope" xmlns:a="http://www.w3.org/2005/08/addressing">
  <s:Header>
    <a:Action s:mustUnderstand="1">http://www.as.com/ver/ver.IClaimver/Car</a:Action>
    <a:MessageID>urn:uuid:b22149b6-2e70-46aa-8b01-c2841c70c1c7</a:MessageID>
    <ActivityId CorrelationId="16b385f3-34bd-45ff-ad13-8652baeaeb8a" xmlns="http://schemas.microsoft.com/2004/09/ServiceModel/Diagnostics">04eb5b59-cd42-47c6-a946-d840a6cde42b</ActivityId>
    <a:ReplyTo>
      <a:Address>http://www.w3.org/2005/08/addressing/anonymous</a:Address>
    </a:ReplyTo>
    <a:To s:mustUnderstand="1">http://localhost/ver.Web/ver2011.svc</a:To>
  </s:Header>
  <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <Car xmlns="http://www.as.com/ver">
      <carApplication>
        <HB_Base xsi:type="HB" xmlns="urn:core">
          <Header>
            <Advisor>
              <AdvisorLocalAuthorityCode>11</AdvisorLocalAuthorityCode>
              <AdvisorType>1</AdvisorType>
            </Advisor>
          </Header>
          <General>
            <ApplyForHB>yes</ApplyForHB>
            <ApplyForCTB>yes</ApplyForCTB>
            <ApplyForFSL>yes</ApplyForFSL>
            <ConsentSupplied>no</ConsentSupplied>
            <SupportingDocumentsSupplied>no</SupportingDocumentsSupplied>
          </General>
        </HB_Base>
      </carApplication>
    </Car>
  </s:Body>
</s:Envelope>

Update

How to use XmlDocument.SelectSingleNode() that uses XmlNamespaceManager. Because it might be better to use xpath like "/Envelope/Body/Car/carApplication/HB_Base"

Answer 1

You need to specify the namespace, using XLinq we’d use an XNamespace to help make the XName which refers to the elements:

var xdoc = XDocument.Load(xmlFile); // or .Parse(@"....")

XNamespace ns = @"urn:core";
// This is where the magic happens: ns + "HB_Base"
var hbBase = xdoc.Root.Descendants(ns + "HB_Base")
                      .SingleOrDefault();

if (hbBase == null) throw new InvalidOperationException("No such element");

var xml = hbBase.ToString();

Using XmlDocument and XmlNamespaceManager instead:

var xmlDoc = new XmlDocument();
xmlDoc.Load(xmlFile);

var nsManager = new XmlNamespaceManager(xmlDoc.NameTable);
nsManager.AddNamespace("s", @"http://www.w3.org/2003/05/soap-envelope");
nsManager.AddNamespace("c", @"http://www.as.com/ver");
nsManager.AddNamespace("h", @"urn:core");

var hbBase = xmlDoc.SelectSingleNode(
    @"/s:Envelope/s:Body/c:Car/c:carApplication/h:HB_Base");
if (hbBase == null) throw new InvalidOperationException("No such element");

var xml = hbBase.OuterXml;