Performing XPath Queries on documents with default namespaces [duplicate]

This question already has answers here: Closed 11 years ago.

Possible Duplicate:

Using Xpath With Default Namespace in C#

Hello,

I'm having a hard time doing xpath on diabolical XML for an integration component. The problem is that some nodes are namespace prefixed and other aren't.

I have a sample XML that declares a default ns and then some particular NS's for other element:

<?xml version="1.0" encoding="UTF-8"?>
<Header xmlns="http://namespaceFoo.com">
    <MessageID>1300121668281</MessageID>
    <OriginIdentificaton>
        <Code>2050302</Code>
    </OriginIdentificaton>
    <PatientData>
        <n开发者_运维知识库s1:Identificacao xmlns:ns1="http://namespaceBAR.com">
            <ns1:SSN>123456789</ns1:SSN>
            <ns1:Name>Johnny john</ns1:Name>
        </ns1:Identificacao>
        <ns2:Diagnosis xmlns:ns2="http://namespaceBAR.com"/>
        <ns3:Contacts xmlns:ns3="http://namespaceBAR.com"/>
        <ns4:Benefits xmlns:ns4="http://namespaceBAR.com"/>
    </PatientData>
</Header>

And I'm trying to query it with something like:

XmlDocument xmlData = new XmlDocument and LoadXml()
XmlNamespaceManager xmlnsManager = new XmlNamespaceManager(xmlData.NameTable);
xmlnsManager.AddNamespace(String.Empty, "http://namespaceFoo.com");
XmlNode n1 = xmlData.SelectSingleNode("/Header");

Which returns Null.

I'm totally lost. I've tried several combinations of namespaces and xpath queries to no avail.

Shouldn't this be trivially simple? Is there a way to query "/Element1/Element2/..." regardless of the namespace of these elements?

Thanks

---

You're so close! You need to first give your empty namespace a "fake" prefix (first line below) and then pass the XmlNamespaceManager into the SelectSingleNode function.

xmlnsManager.AddNamespace("x", "http://namespaceFoo.com");
XmlNode n1 = xmlData.SelectSingleNode("/Header", xmlnsManager);