How to change innertext of an xml file

Question

Hi,

 

Now that I can read my xml-file from my richtextbox I would like to change some innertext in the childnodes and whatch the changes in my richtextbox. How should I do this please? Because my code isn't working.

 

 

//Read selected file.

XmlDocument doc = new XmlDocument();

doc.LoadXml(richTextBox1.Text);

XmlNodeList nodeList = doc.DocumentElement.SelectNodes("/AnXMLTestFile/"); //<== error message "Expression must evaluate to a node-set."

//find the node to change the content

//if node is not present, do nothing

foreach (XmlNode xNode in nodeList)

{

if (xNode.ParentNode.Attributes["HeaderBEDocument"].Value != "")

{

doc.SelectSingleNode("Identification").InnerText = "string";

doc.SelectSingleNode("SCI").InnerText = "string";

doc.SelectSingleNode("ReferenceType").InnerText = "string";

doc.SelectSingleNode("CCType").InnerText = "AA";

}

else { } //do nothing

}

 

Can someone help me please?

Thanks in advance.