问题
There are several related questions, but none which provide the guidance I need.
Assuming the following XML:
<?xml-stylesheet href="http://www.blogger.com/styles/atom.css" type="text/css"?>
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:openSearch="http://a9.com/-/spec/opensearchrss/1.0/" xmlns:blogger="http://schemas.google.com/blogger/2008" xmlns:georss="http://www.georss.org/georss" xmlns:gd="http://schemas.google.com/g/2005" xmlns:thr="http://purl.org/syndication/thread/1.0" >
<entry>
<title type="text">This is the title</title>
<content>lorem ipsum</content>
</entry>
<entry>
<title type="text">This is the second title</title>
<content>lorem ipsum 2</content>
</entry>
</feed>
If this document had no namespaces, I could write code like this:
Public Sub ShowXML(XmlText As String)
Dim doc As New XmlDocument
doc.LoadXml(XmlText)
For Each Entry As XmlNode In doc.SelectNodes("//entry")
Console.WriteLine(Entry.SelectSingleNode("title").InnerText)
Next
End Sub
Because of namespaces, this is not possible. This is my latest attempt:
Public Sub ShowXML(XmlText As String)
Dim doc As New XmlDocument
doc.LoadXml(XmlText)
Dim nsmgr As New XmlNamespaceManager(doc.NameTable)
nsmgr.AddNamespace("rss", "http://www.w3.org/2005/Atom")
For Each Entry As XmlNode In doc.SelectNodes("//rss:entry")
Console.WriteLine(Entry.SelectSingleNode("/rss:title").InnerText)
Next
End Sub
What is the correct XPath syntax to get the "title"?
Reasons why this is a separate question from other ones on similar topics:
- Most of the other examples are C#, and I am looking for a VB.NET solution.
- The other examples do not address the scenario of navigating to a node from a previously-selected node.
I am not looking for a solution that strips namespaces; I want to understand them. Thank you.
回答1:
Your inner XPath, /rss:title
, has a leading /
which indicates that this search should begin from the top of the document regardless of the fact that you are currently on a child node.
Instead just use rss:title
and you'll get the node you are after.
来源:https://stackoverflow.com/questions/16949495/using-xpath-and-vb-net-to-parse-xml-containing-namespsaces