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  • .NET XmlNavigator with Namespace

    In .NET 2.0 there is additional overload that accepts string expression
    and IXmlNamespaceResolver (XmlNamespaceManager implements it) - see
    http://msdn2.microsoft.com/en-us/library/6k4x060d.aspx.

    XPathDocument document = new XPathDocument("contosoBooks.xml");
    XPathNavigator navigator 
    = document.CreateNavigator();

    XmlNamespaceManager manager 
    = new XmlNamespaceManager(navigator.NameTable);
    manager.AddNamespace(
    "bk""http://www.contoso.com/books");

    XPathNodeIterator nodes 
    = navigator.Select("/bk:bookstore/bk:book", manager);
    XPathNavigator nodesNavigator 
    = nodes.Current;

    XPathNodeIterator nodesText 
    = nodesNavigator.SelectDescendants(XPathNodeType.Text, false);

    while (nodesText.MoveNext())
    {
        Console.Write(nodesText.Current.Name);
        Console.WriteLine(nodesText.Current.Value);
    }


    In .NET 1.1 you have no choice but to compile XPathExpression manually:

    XPathExpression expr = nav.Compile("book/@bk:ISBN");
    XmlNamespaceManager mngr = new XmlNamespaceManager(new NameTable());
    mngr.AddNamespace("bk","urn:samples");
    expr.SetContext(mngr);
    XPathNodeIterator ni = nav.Select(expr);

    See
    http://msdn.microsoft.com/library/d...ecttopic2 .asp

    --------------------------------------------------------------------------------


    Thanks Oleg, it works a treat (but what a polaver though).

    One small follow-up if I may. I would have thought that if I initialized the
    namespace manager like this:

    XmlNamespaceManager mngr = new XmlNamespaceManager(nav.NameTable);

    then it would pick up the namespace prefixes from the document. However, it
    doesn't (I still need to do the AddNamespace calls)

     --------------------------------------------------------------------------------

    No, first of all NameTable has nothing to do with namespaces - it's just
    a collection of atomic strings (names) used to save memory and speed
    up name comparisons. Second - there is no such thing as "prefixes from
    the document" as in XML document namespace prefixes can be overriden and
    undeclared in any order.

    The NameTable is used to speed up string comparison, there is nothing
    done like "picking up namespace prefixes".
    As said, with .NET 2.0 you have some way to use the XPathNavigator
    itself, once moved to the proper node you want to "pick up namespace
    prefixes" from, itself as the namespace manager.
    <http://groups.google.com/group/microsoft.public.dotnet.xml/msg/af7d7f9e2f422d7e?hl=en&>

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  • 原文地址:https://www.cnblogs.com/mrfangzheng/p/1140591.html
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