SelectSingLenode Retour NULL - Même avec espace de noms

Question

Je sais que cette question a été posée de la même manière, mais je ne peux pas sembler obtenir ce travail.

J'ai du XML:

<?xml version="1.0" encoding="ISO-8859-1" ?> 
    <Research xmlns="http://www.rixml.org/2005/3/RIXML" xmlns:xalan="http://xml.apache.org/xalan" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" createDateTime="2011-03-29T15:41:48Z" language="eng" researchID="MusiJvs3008">
    <Product productID="MusiJvs3008">
    <StatusInfo currentStatusIndicator="Yes" statusDateTime="2011-03-29T15:41:48Z" statusType="Published" />
    <Source>
    <Organization type="SellSideFirm" primaryIndicator="Yes">
    <OrganizationID idType="Reuters">9999</OrganizationID> 

Et j'essaie de lire des valeurs à l'aide de XPATH:

XPathDocument xmldoc = new XPathDocument(xmlFile); 
XPathNavigator nav = xmldoc.CreateNavigator(); 
XmlNamespaceManager nsMgr = new XmlNamespaceManager(nav.NameTable);
nsMgr.AddNamespace(string.Empty, "http://www.rixml.org/2005/3/RIXML"); 
XPathNavigator result = nav.SelectSingleNode("/Research", nsMgr); // <-- Returns null!

Mais même une simple sélection du nœud racine retourne null!Je suis sûr que j'ai quelque chose qui ne va pas avec mon espace de noms.Quelqu'un peut-il vous aider?

Idéalement, je veux des lignes simples qui me permettront de sélectionner des valeurs dans le fichier XML, c'est-à-dire.

String a = xmlDoc.SelectSingleNode(@"/Research/Product/Content/Title").Value;

BTW, je n'ai pas de contrôle (direct) sur le contenu du fichier XML.

Answer 1

I don't believe you can use an empty namespace alias and have it used automatically by the XPath expression. As soon as you use an actual alias, it should work though. This test is fine, for example:

using System;
using System.Xml;
using System.Xml.XPath;

class Test
{
    static void Main() 
    {
        string xmlFile = "test.xml";
        XPathDocument xmldoc = new XPathDocument(xmlFile); 
        XPathNavigator nav = xmldoc.CreateNavigator(); 
        XmlNamespaceManager nsMgr = new XmlNamespaceManager(nav.NameTable);
        nsMgr.AddNamespace("x", "http://www.rixml.org/2005/3/RIXML"); 
        XPathNavigator result = nav.SelectSingleNode("/x:Research", nsMgr);
        Console.WriteLine(result);
    }
}

Do you have to use XPath and XPathDocument, by the way? I tend to find that LINQ to XML is a much more pleasant API, particularly when it comes to namespaces. If you're using .NET 3.5 and you have no particular requirement to use XPath, I'd suggest you check it out.

Answer 2

Make the following changes

nsMgr.AddNamespace("x", "http://www.rixml.org/2005/3/RIXML"); 
XPathNavigator result = nav.SelectSingleNode("/x:Research", nsMgr);

Answer 3

i could post, and answer my own question, for the native equivalent of this code. Instead i'll just add it as an answer to the end.

When using the native IXMLDOMDocument (version 6) object:

//Give the default namespace as alias of "x"
document.setProperty("SelectionNamespaces","xmlns:x='http://www.rixml.org/2005/3/RIXML'");

//Query for the nodes we want
document.selectSingleNode("/x:Research");

Bonus Question: Why, oh why, does no Xml Document object model query the default namespace when no namespace is specified... sigh