In C#, you can read XML files using the System.Xml namespace, which provides classes like XmlDocument, XmlTextReader, and XDocument for parsing and working with XML data. Here, I'll provide a sample using both XmlDocument and XDocument to read an XML file:

Sample XML File (example.xml):

<?xml version="1.0" encoding="UTF-8"?>
<root>
  <person>
    <name>John Doe</name>
    <age>30</age>
  </person>
  <person>
    <name>Jane Smith</name>
    <age>25</age>
  </person>
</root>

Reading XML using XmlDocument:

using System;
using System.Xml;

class Program
{
    static void Main()
    {
        // Load the XML file
        XmlDocument doc = new XmlDocument();
        doc.Load("example.xml");

        // Select the root node
        XmlNode root = doc.DocumentElement;

        // Select child nodes
        XmlNodeList personNodes = root.SelectNodes("person");

        // Iterate through the person nodes
        foreach (XmlNode personNode in personNodes)
        {
            string name = personNode.SelectSingleNode("name").InnerText;
            int age = int.Parse(personNode.SelectSingleNode("age").InnerText);

            Console.WriteLine($"Name: {name}, Age: {age}");
        }
    }
}

Reading XML using XDocument (LINQ to XML):

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

class Program
{
    static void Main()
    {
        // Load the XML file
        XDocument doc = XDocument.Load("example.xml");

        // Query elements using LINQ to XML
        var persons = from person in doc.Descendants("person")
                      select new
                      {
                          Name = (string)person.Element("name"),
                          Age = (int)person.Element("age")
                      };

        // Iterate through the selected elements
        foreach (var person in persons)
        {
            Console.WriteLine($"Name: {person.Name}, Age: {person.Age}");
        }
    }
}

Both XmlDocument and XDocument provide methods for loading and querying XML data. XDocument is part of LINQ to XML and is often preferred for its simplicity and integration with LINQ. Choose the one that best fits your needs and coding style.