[Solved] What is the fastest way to go through a XML file in C#?

Question

Here is the example, which reads sample XML and shows comparison between Linq/XMlReader and XmlDocument

Linq is fastest.

Sample Code

using System;
using System.Diagnostics;
using System.Linq;
using System.Xml;
using System.Xml.Linq;

namespace ReadXMLInCsharp
{
  class Program
  {
    static void Main(string[] args)
    {
     
        //returns url of main directory which contains "/bin/Debug"
        var url=System.IO.Path.GetDirectoryName(
System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase);
        
        //correction in path to point it in Root directory
        var mainpath = url.Replace("\\bin\\Debug", "") + "\\books.xml";

        var stopwatch = new Stopwatch();
        stopwatch.Start();

        //create XMLDocument object
        XmlDocument xmlDoc = new XmlDocument();
        //load xml file
        xmlDoc.Load(mainpath);
        //save all nodes in XMLnodelist
        XmlNodeList nodeList = xmlDoc.DocumentElement.SelectNodes("/catalog/book");

        //loop through each node and save it value in NodeStr
        var NodeStr = "";

        foreach (XmlNode node in nodeList)
        {
            NodeStr = NodeStr + "\nAuthor " + node.SelectSingleNode("author").InnerText;
            NodeStr = NodeStr + "\nTitle " + node.SelectSingleNode("title").InnerText;
            NodeStr = NodeStr + "\nGenre " + node.SelectSingleNode("genre").InnerText;
            NodeStr = NodeStr + "\nPrice " + node.SelectSingleNode("price").InnerText;
            NodeStr = NodeStr + "\nDescription -" + node.SelectSingleNode("description").InnerText;


        }
        //print all Authors details
        Console.WriteLine(NodeStr);
        stopwatch.Stop();
        Console.WriteLine();
        Console.WriteLine("Time elapsed using XmlDocument (ms)= " + stopwatch.ElapsedMilliseconds);
        Console.WriteLine();

        stopwatch.Reset();

        stopwatch.Start();
        NodeStr = "";
        //linq method
        //get all elements inside book
        foreach (XElement level1Element in XElement.Load(mainpath).Elements("book"))
        {
            //print each element value
            //you can also print XML attribute value, instead of .Element use .Attribute
            NodeStr = NodeStr + "\nAuthor " + level1Element.Element("author").Value;
            NodeStr = NodeStr + "\nTitle " + level1Element.Element("title").Value;
            NodeStr = NodeStr + "\nGenre " + level1Element.Element("genre").Value;
            NodeStr = NodeStr + "\nPrice " + level1Element.Element("price").Value;
            NodeStr = NodeStr + "\nDescription -" + level1Element.Element("description").Value;
        }

        //print all Authors details
        Console.WriteLine(NodeStr);
        stopwatch.Stop();
        Console.WriteLine();
        Console.WriteLine("Time elapsed using linq(ms)= " + stopwatch.ElapsedMilliseconds);
        Console.WriteLine();

        stopwatch.Reset();
        stopwatch.Start();
        //method 3
        //XMLReader
        XmlReader xReader = XmlReader.Create(mainpath);

        xReader.ReadToFollowing("book");
        NodeStr = "";
        while (xReader.Read())
        {
            switch (xReader.NodeType)
            {
                case XmlNodeType.Element:
                    NodeStr = NodeStr + "\nElement name:" + xReader.Name;
                    break;
                case XmlNodeType.Text:
                    NodeStr = NodeStr + "\nElement value:" + xReader.Value;
                    break;
                case XmlNodeType.None:
                    //do nothing
                    break;

            }
        }

        //print all Authors details
        Console.WriteLine(NodeStr);
        stopwatch.Stop();
        Console.WriteLine();
        Console.WriteLine("Time elapsed using XMLReader (ms)= " + stopwatch.ElapsedMilliseconds);
        Console.WriteLine();
        stopwatch.Reset();


        Console.ReadKey();
    }
  }
}

Output:

-- First Run
Time elapsed using XmlDocument (ms)= 15

Time elapsed using linq(ms)= 7

Time elapsed using XMLReader (ms)= 12

-- Second Run
Time elapsed using XmlDocument (ms)= 18

Time elapsed using linq(ms)= 3

Time elapsed using XMLReader (ms)= 15

I have removed some output to show only comparison data.

Source: Open and Read XML in C# (Examples using Linq, XMLReader, XMLDocument)

Edit: If i comment ‘Console.WriteLine(NodeStr)‘ from all methods and prints only time comparison.
This is what I get

Time elapsed using XmlDocument (ms)= 11


Time elapsed using linq(ms)= 0


Time elapsed using XMLReader (ms)= 0

Basically it depends on how you are processing the data and how you are reading XML.
Linq/XML reader once look more promising in terms of speed.

Accepted Answer