Check if XML Element exists

Question

How can someone validate that a specific element exists in an XML file? Say I have an ever changing XML file and I need to verify every element exists before reading/parsing

Answer 1

//Check xml element value if exists using XmlReader

          using (XmlReader xmlReader = XmlReader.Create(new StringReader("XMLSTRING")))
           {

               if (xmlReader.ReadToFollowing("XMLNODE")) 

                {
                    string nodeValue = xmlReader.ReadElementString("XMLNODE");                
                }
            }