C#, XML, adding new nodes

Question

I am trying to add new nodes to an existing XML file. i have this file with first test elements in it:

 
<         


        

Answer 1

I have the same trouble, with root==null, but MSDN helped me.

You need to use // instead of /

XmlNode root = xmldoc.SelectSingleNode("//ns:Root//ns:profesori", nsMgr);

Answer 2

Your first problem is that the node names in your XPath don't match those of the XML. XML is case sensitive, so you need to use Root, not root:

XmlNode root = xmldoc.SelectSingleNode("/ns:Root/ns:profesori", nsMgr);

Next, instead of xmldoc.NamespaceURI, use the actual namespace uri:

string strNamespace= "http://prpa.org/XMLSchema1.xsd";
nsMgr.AddNamespace("ns", strNamespace);

or do this:

string strNamespace= xmldoc.DocumentElement.NamespaceURI;
nsMgr.AddNamespace("ns", strNamespace);

The NamespaceURI of an XmlDocument object will always be an empty string.

And you should also use this namespace when creating your elements:

XmlNode prof = xmldoc.CreateNode(XmlNodeType.Element, "profesor", strNamespace);

XmlNode ime = xmldoc.CreateNode(XmlNodeType.Element, "ime", strNamespace);
ime.InnerText = name;
prof.AppendChild(ime);

XmlNode prezime = xmldoc.CreateNode(XmlNodeType.Element, "prezime", strNamespace);
prezime.InnerText = surname;
prof.AppendChild(prezime);

root.AppendChild(prof);

You might also consider using the CreateElement() method, which would be slightly shorter:

XmlNode prof = xmldoc.CreateElement("profesor", strNamespace);

Or, my preference would be to use an XmlWriter:

using(XmlWriter writer = root.CreateNavigator().AppendChild())
{
    writer.WriteStartElement("profesor", strNamespace);
    writer.WriteElementString("ime", strNamespace, name);
    writer.WriteElementString("prezime", strNamespace, surname);
    writer.WriteEndElement();
}