How to manage a XML tag with a colon on C# with a local-name XPATH

Question

This a simplified version of a more complex XML that I need to manage with C#.

The problem is that when I try to access to a tag within a namespace, the XPATH does not work.

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml("<s:Body xmlns:s=\"sssssss\"><s:SessionID>abcde</s:SessionID></s:Body>");
string xpath = "//*[local-name()='s:SessionID']";
Context.UserLogger.Info(xmlDoc.SelectSingleNode(xpath).InnerText);
//Object reference not set to an instance of an object

But the code works perfect without the colon on the tag.

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml("<s:Body xmlns:s=\"sssssss\"><SessionID>abcde</SessionID></s:Body>");
string xpath = "//*[local-name()='SessionID']";
Context.UserLogger.Info(xmlDoc.SelectSingleNode(xpath).InnerText);
//abcde

I have ensured on a XPATH validator that the "//*[local-name()='s:SessionID']" works fine.

What I am missing?

Thanks in advance,

I have read info about XmlNamespaceManager but I would prefer to use "direct" paths. The XML is full of NameSpaces and it is dynamic, so its the structure changes quite often.

Answer 1

the function local-name() returns only the local part of a tag name that in your case is exactly SessionID that's why the expression '//*[local-name()='s:SessionID']' doesn't work (you need to compare qualified names not just strings) From your question it seems to me that your are interested in selecting the SessionsID elements, if it's so use just the xpath expression

string xpath = "//s:SessionID";

if it doesn't works then you probably need to bound the prefix s with the namespace uri s="sssssss" (take from your example)