XmlNodeList (why is this empty)

I can't understand why this NodeList is Empty

XmlDocument document = new XmlDocument();
document.Load(xmlpath);    
XmlNodeList nodes = document.SelectNodes("/StructureResponse/rootItem/attributes/Attribute");

Here the XmlFile

<?xml version="1.0" encoding="utf-8"?>
<StructureResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://nts-de-osm1-pxc/webservices/">
    <consolidatedItems xsi:nil="true" xmlns="http://systinet.com/wsdl/com/osm/webservices/service/" />
    <rootItem xsi:type="Part" xmlns="http://systinet.com/wsdl/com/osm/webservices/service/">
        <attributes>
            <Attribute>
                <dataDictionary xsi:nil="true" />
                <dataType>string</dataType>
                <displayName>IDENT_NR</displayName>
                <key>true</key><name>IDENT_NR</name>
                <searchable>true</searchable>
                <userAttribute>true</userAttribute>
                <value>9662744</value>
            </Attribute>
            <Attribute>
                <dataDictionary xsi:nil="true" />
                <dataType>string</dataType>
                <displayName>AI</displayName>
                <key>开发者_JAVA百科true</key><name>AI</name>
                <searchable>true</searchable>
                <userAttribute>true</userAttribute>
                <value>00</value>
            </Attribute>
        </rootItem>
    </StructureResponse>

In the Final Script I want to get an array string which contains every Attribute in it.

Thank you Stefan

You're not taking into account the XML namespace (xmlns="http://nts-de-osm1-pxc/webservices/") on the document!

OK, you even have two separate namespaces - updated my sample.

Try this:

XmlDocument document = new XmlDocument();
document.Load(xmlpath);    

XmlNamespaceManager mgr = new XmlNamespaceManager(document.NameTable);
mgr.AddNamespace("ns", "http://nts-de-osm1-pxc/webservices/"); 
mgr.AddNamespace("root", "http://systinet.com/wsdl/com/osm/webservices/service/");

XmlNodeList nodes = document.SelectNodes("/ns:StructureResponse/root:rootItem/root:attributes/root:Attribute", mgr);

Marc

User marc_s's answer is actually correct. You need to pay attention to the XML namespaces. His code sample, however, will not work directly for your example. Here is a full sample that works with the XML you gave (although I had to clean it up... it was missing a closing tag for attributes).

string xmlData = 
@"<?xml version='1.0' encoding='utf-8'?>
  <StructureResponse
     xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' 
     xmlns:xsd='http://www.w3.org/2001/XMLSchema'
     xmlns='http://nts-de-osm1-pxc/webservices/'>
    <consolidatedItems xsi:nil='true' xmlns='http://systinet.com/wsdl/com/osm/webservices/service/' />
    <rootItem xsi:type='Part' xmlns='http://systinet.com/wsdl/com/osm/webservices/service/'>
      <attributes>
        <Attribute>
          <dataDictionary xsi:nil='true' />
          <dataType>string</dataType>
          <displayName>IDENT_NR</displayName>
          <key>true</key>
          <name>IDENT_NR</name>
          <searchable>true</searchable>
          <userAttribute>true</userAttribute>
          <value>9662744</value>
        </Attribute>
        <Attribute>
          <dataDictionary xsi:nil='true' />
          <dataType>string</dataType>
          <displayName>AI</displayName>
          <key>true</key>
          <name>AI</name>
          <searchable>true</searchable>
          <userAttribute>true</userAttribute>
          <value>00</value>
        </Attribute>
      </attributes>
      </rootItem>
  </StructureResponse>";

XmlDocument document = new XmlDocument();
XmlNamespaceManager namespaceManager = new XmlNamespaceManager(document.NameTable);
namespaceManager.AddNamespace("a", "http://nts-de-osm1-pxc/webservices/");
namespaceManager.AddNamespace("b", "http://systinet.com/wsdl/com/osm/webservices/service/");
document.LoadXml(xmlData);
XmlNodeList nodes = document.SelectNodes("/a:StructureResponse/b:rootItem/b:attributes/b:Attribute", namespaceManager);
// 'nodes' contains 2 items now, as expected

I suggest doing a bit more studying of XML namespaces. Try skimming Ronald Bourret's "XML Namespaces FAQ".

Try:

XmlNodeList nodes = document.SelectNodes("./StructureResponse/rootItem/attributes");