// XPath namespace query sample by Bulent Ozkir (bulento@microsoft.com)
 
using System;
using System.Xml;
using System.Xml.XPath;
using System.Collections;
 
public class XMLApp
{
 
 public static void Main( String[] args)
 {
 
  try
  {
   // namespace_URI array
   ArrayList arr1 = new ArrayList();
   // namespace_name array
   ArrayList arr2 = new ArrayList();
 
   XmlDocument _doc = new XmlDocument();
   _doc.LoadXml(@"<Schema name=""BlankSpecification""   
   xmlns=""urn:schemas-microsoft-com:xml-data"" 
   xmlns:b=""urn:schemas-microsoft-com:BizTalkServer"" 
   xmlns:d=""urn:schemas-microsoft-com:datatypes""></Schema>");
   XmlNodeList nl2 = _doc.SelectNodes(@"//namespace::node()");
  
   foreach (XmlNode n in nl2)
   {
    if( arr1.IndexOf(n.Value) == -1 && arr2.IndexOf(n.Name) == -1)
    {
     Console.WriteLine("<" + n.Value + ">");
     Console.WriteLine("<" + n.Name + ">");
     arr1.Add(n.Value);    
     arr2.Add(n.Name);
    }
   }
   Console.WriteLine("Total Number of namespace URIs=" + arr1.Count);
   Console.WriteLine("Total Number of namespace names=" + arr2.Count);
 
   /* output:
   <urn:schemas-microsoft-com:datatypes>
   <xmlns:d>
   <urn:schemas-microsoft-com:BizTalkServer>
   <xmlns:b>
   <urn:schemas-microsoft-com:xml-data>
   <xmlns>
   <http://www.w3.org/XML/1998/namespace>
   <xmlns:xml>
   Total Number of namespace URIs=4
   Total Number of namespace names=4 
   */
 
  }
  catch(Exception e) 
  { 
   Console.WriteLine ("Exception: {0}", e.ToString()); 
  }          
 }
}