Undeclared Namespace in XML (eg: xsi is an undeclared namespace)

If you XML source publishes invalid XML for some reason ( i.e. it has Xml elements referring to undeclared namespace ) and you try to load this XML in XMLDocument. You would end up getting exception similar to <NameSpace> is an undeclared namespace.

eg:

 <?xml version="1.0" encoding="utf-16"?>

<root>

<Name xsi:nil="true">name1</Name>

<Name xsi:nil="true">name2</Name>

<Name xsi:nil="true">name3</Name>

</root>

Ideally this is an Invalid XML but there is a way to load it in XMLDocument using following code snippet.

            XmlDocument doc = new XmlDocument();

            NameTable nt = new NameTable();

            XmlNamespaceManager nsmgr = new XmlNamespaceManager(nt);

            nsmgr.AddNamespace("xsi", "https://www.w3.org/2001/XMLSchema-instance");

            XmlParserContext context = new XmlParserContext(null, nsmgr, null, XmlSpace.None);

            XmlReaderSettings xset = new XmlReaderSettings();

            xset.ConformanceLevel = ConformanceLevel.Fragment;

            XmlReader rd = XmlReader.Create(new  StringReader(XMLSource), xset, context); 

            doc.Load(rd);

Runeet Vashisht

Comments

• Anonymous
  October 17, 2012
  This is awesome, exactly what I need. I knew I had to somehow inject a declaration into the nametable, but it wasn't obvious how to do that when I was trying to use the LoadXml() method. Thakyou very much!

• Anonymous
  October 28, 2014
  Thank you for a quick fix to and obvious issue