using System;

using System.Collections.Generic;

using System.Linq;

using System.Xml.Serialization;

using System.Xml;

using System.Xml.Linq;

using System.Xml.Schema;

using System.IO;

using System.Diagnostics;

​

    public class Program

    {

        static string GetXml()

        {

            var xml = @"<?xml version=""1.0"" encoding=""utf-8""?>

<CollectionPlan xmlns=""urn:schemas-microsoft-com:visualstudio:tracelog"">

  <StartupInfo>

    <LogFileName>

    </LogFileName>

    <LogFileDirectory>C:\LogFiles</LogFileDirectory>

    <MaximumLogFileSize>16384</MaximumLogFileSize>

  </StartupInfo>

  <CheckpointOptions>

    <ThreadCheckpoints>

      <Mode>FixedEventRate</Mode>

      <StartRate>30000</StartRate>

    </ThreadCheckpoints>

    <NotifyPointCheckpoints>

      <Mode>FixedEventRate</Mode>

      <StartRate>1000</StartRate>

    </NotifyPointCheckpoints>

  </CheckpointOptions>

  <!-- many other nodes -->

 </CollectionPlan>";

            return xml;

        }

​

        public static void Main()

        {

            XmlDocument doc = new XmlDocument();

            XmlNamespaceManager manager = new XmlNamespaceManager(doc.NameTable);

            manager.AddNamespace("urn", "urn:schemas-microsoft-com:visualstudio:tracelog");

            doc.LoadXml(GetXml());

            var aNodes = doc.SelectSingleNode("urn:CollectionPlan/urn:CheckpointOptions/urn:ThreadCheckpoints/urn:Mode", manager);

​

            Console.WriteLine(aNodes == null ? "null" : aNodes.OuterXml);

        }

    }