与XML名称空间（linq）纠缠...在这里我做错了什么？

Question

Trying to parse some XML but apparently this is too much for a lazy sunday afternoon,

this is my code: (I Tried the XPathDocument and XmlDocument approach too but this also failed miserably)

 XmlDocument xmlDoc = new XmlDocument();
 xmlDoc.LoadXml(postData);
 XDocument xDoc = XDocument.Load(new XmlNodeReader(xmlDoc)); 
 XNamespace soapEnv = "http://schemas.xmlsoap.org/soap/envelope/";
 XElement xEnv = xDoc.Descendants(soapEnv + "Envelope").First();
 XElement xBody = xEnv.Descendants(soapEnv + "Body").First();
 XElement xReadReply = xBody.Descendants("ReadReplyReq").First();

The last line fails with the exception: no elements in this collection however if I change this last line into:

 XElement xReadReply = xBody.Descendants().First();

it returns the first node which in fact is the "ReadReplyReq" node.

Having finally gotten these Namespaces working, it now fails on the first node without a namepace... ooh bitter irony ;^)

This is the XML I'm trying to parse:

 <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
      <SOAP-ENV:Header>
           <TransactionID xmlns="http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-2" SOAP-ENV:actor="" SOAP-ENV:mustUnderstand="1">12345678</TransactionID>
      </SOAP-ENV:Header>
      <SOAP-ENV:Body>
           <ReadReplyReq xmlns="http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-2">
                <MMStatus>Read</MMStatus>
                <TimeStamp>2007-12-13T14:05:27+01:00</TimeStamp>
                <MessageID>54321</MessageID>
                <Sender>
                     <ShortCode>+12345</ShortCode>
                </Sender>
                <Recipient>
                     <Number>+12345</Number>
                </Recipient>
                <StatusText>Message has been read</StatusText>
                <MM7Version>5.3.0</MM7Version>
           </ReadReplyReq>
       </SOAP-ENV:Body>
 </SOAP-ENV:Envelope>

what last step am I missing here?

ps and why can't the XPath not just be something more intuitive like: "//SOAP-ENV:Envelope/SOAP-ENV:Body/ReadReplyReq/MMStatus", instead of all these crazy hoops one has to jump through.

Answer 1

I am guessing what you want is to add a namespace manager so you can XPath select on prefixed nodes?

If so then something like:

var doc = new XmlDocument();

doc.LoadXml( postData );
var ns = new XmlNamespaceManager( doc.NameTable );
ns.AddNamespace( "SOAP-ENV", "http://schemas.xmlsoap.org/soap/envelope/" );
ns.AddNamespace( "def", "http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-2" );
XmlNode list = doc.SelectSingleNode( "//SOAP-ENV:Envelope/SOAP-ENV:Body/def:ReadReplyReq/def:MMStatus", ns );

Is probably what you want.

Answer 2

You don't need XPath you just need a namespace for the xReadReply element. Declare the namespace just like you did for the soap elements and use it when searching for that element.

XNamespace transNS = "http://www.3gpp.org/ftp/Specs/archive/23_series/23.140/schema/REL-5-MM7-1-2";

XElement xReadReply = xBody.Descendants( transNS + "ReadReplyReq" ).First();