XDocument.Descendants(itemName) - Problems finding qualified name

问题

I'm trying to read a XML-RSS-Feed from a website. Therefore I use a async download and create a XDocument with the XDocument.Parse() Method.

The Document intends to be very simple, like this:

<root>
  <someAttribute></SomeAttribute>
  <item>...</item>
  <item>...</item>
</root>

Now I want to read out all the items. Therefore I tried:

foreach (XElement NewsEntry in xDocument.Descendants("item"))

but this doesn't work. So I found a post in this board to use the qualified name, because there are some namespaces defined in the root element:

<?xml version="1.0" encoding="ISO-8859-1" ?> 
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:sy="http://purl.org/rss/1.0/modules/syndication/" xmlns="http://purl.org/rss/1.0/">

well, I tried all 3 available namespaces - nothing worked for me:

XName itemName = XName.Get("item", "http://www.w3.org/1999/02/22-rdf-syntax-ns#");
XName itemName2 = XName.Get("item", "http://purl.org/dc/elements/1.1/");
XName itemName3 = XName.Get("item", "http://purl.org/rss/1.0/modules/syndication/");

Any help would be appreciated. (Usually I'm doing the XML-Analysis with Regex - but this time I'm developing for a mobile device, and therefore need to care about performance.)

回答1:

You have not tried the default namespace at the end of the rdf declaration:

xmlns="http://purl.org/rss/1.0/"

This makes sense, as any element in the default namespace will not need to have the namespace prepended to the element name.

回答2:

Not directly a solution to the XDocument RSS read problem. But why aren't you using the provided SyncdicationFeed class to load the feed? http://msdn.microsoft.com/en-us/library/system.servicemodel.syndication.syndicationfeed.aspx

回答3:

Try this

var elements = from p in xDocument.Root.Elements()
where p.Name.LocalName == "item"
select p;

foreach(var element in elements)
{
//Do stuff
}

来源：https://stackoverflow.com/questions/3924305/xdocument-descendantsitemname-problems-finding-qualified-name