Adding node to existing xml element

Question

I'm getting this error when trying to append a node to existing element in my xml document.The error is: Object reference not set to an instance of an object.

<houses>
  <house windowsc="three">
    <wind>0</wind>
    <windows>
    </windows>
  </house>
</houses>

Code:

XmlDocument xDoc = new XmlDocument();

xDoc.Load("C:\\Houseplans.xml");

XmlElement xhousing = xDoc.DocumentElement["houses/house[@windowsc=\"three\"]/windows"];
XmlNode xName = xDoc.CreateElement("Name");
xName.InnerText = "hi";
xhousing.AppendChild(xName);

Answer 1

You want to use SelectSingleNode:

XmlNode xhousing = xDoc.SelectSingleNode(@"//house[@windowsc='three']/windows");
XmlNode xName = xDoc.CreateElement("Name");
xName.InnerText = "hi";
xhousing.AppendChild(xName);