using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
namespace MyDataTable
{   
    class Program
    {
        static void Main(string[] args)
        {
            DataTable table = new DataTable("myTable");
            //
            //Definujeme typ 
            //
            table.Columns.Add("Id", typeof(int));
            table.Columns.Add("Meno", typeof(string));
            table.Columns.Add("Priezvisko", typeof(string));
            table.Columns.Add("Date", typeof(DateTime));
            //
            // Tu pridame jednotlive riadky tabulky
            //
            table.Rows.Add(0, "Jarko", "Pekny", DateTime.Now);
            table.Rows.Add(2, "Peter", "Odkrasy", DateTime.Now);
            table.Rows.Add(24, "Nicolas", "Christoff", DateTime.Now);
            table.Rows.Add(21, "Janeta", "Vesela", DateTime.Now);
            //
            //Vytvorime xml subor
            //
            table.WriteXml("subor.xml");
            Console.WriteLine("Subor bol vytvoreny");
          
        }
    }
}

Ďalšia možnosť je napr:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
namespace MyDataTable
{
    public class User
    {
        public int Id
        {
            get;
            set;
        }
        public string Meno
        {
            get;
            set;
        }
        public string Priezvisko
        {
            get;
            set;
        }
        public DateTime Date
        {
            get;
            set;
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            DataTable table2 = new DataTable("myTable");
            User myUser = new User();
            //
            //Definujeme typ 
            //
            table2.Columns.Add("User", typeof(User));
            myUser.Id = 0;
            myUser.Meno = "Jarko";
            myUser.Priezvisko = "Pekny";
            myUser.Date = DateTime.Now;
            //
            // Tu pridame jednotlive riadky tabulky
            //
            table2.Rows.Add(myUser);
            //
            //Vytvorime xml subor
            //
            table2.WriteXml("subor2.xml");    
            Console.WriteLine("Subor bol vytvoreny");
          
        }
    }
}

Výstup : xml súbor

<?xml version="1.0" standalone="yes"?>
<DocumentElement>
  <myTable>
    <User xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
      <Id>0</Id>
      <Meno>Jarko</Meno>
      <Priezvisko>Pekny</Priezvisko>
      <Date>2011-11-22T11:11:24.967375+01:00</Date>
    </User>
  </myTable>
</DocumentElement>

Načítanie xml súboru pomocou DataTable

private void citajXML()
{
    try
    {
        DataTable table2 = new DataTable("myTable");
        User myUser = new User();
        table2.Columns.Add("User", typeof(User));
        //nacitanie xml
        table2.ReadXml("subor2.xml");
        //prvy zaznam v xml 
        //pretypujeme na (User)
        myUser = (User)table2.Rows[0][0];
        Console.WriteLine("Meno : " + myUser.Meno + "Priezvisko : " + myUser.Priezvisko);
        Console.ReadKey();
    }
    catch (Exception ex1)
    {
        Console.WriteLine(ex1.Message);
    }
}

Čítanie XML z URL adresy pomocou DataSet

using System;
using System.Net;
using System.Data;
namespace ReadXML
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                string row = String.Empty;
                // Create the web request  
                HttpWebRequest request = WebRequest.Create("http://www.projectik.eu/index.php?option=com_xmap&view=xml&id=1") as HttpWebRequest;
                // Get response  
                               using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    // Load data into a dataset  
                    DataSet myDataSet = new DataSet();
                    myDataSet.ReadXml(response.GetResponseStream());
                    // Print out all tables and their columns  
                   
                    foreach (DataTable table in myDataSet.Tables)
                    {
                        Console.WriteLine("TABLE '{0}'", table.TableName);
                        Console.WriteLine("Total # of rows: {0}", table.Rows.Count);
                        Console.WriteLine("--------------------------------------");
                        //Headers
                        foreach (DataColumn column in table.Columns)
                        {
                            row += "\t" + column.ColumnName +"("+column.DataType.ToString()+")";
                        }
                        Console.WriteLine("{0}", row);
                        //Rows
                        foreach (DataRow row1 in table.Rows)
                        {
                            foreach (string column in row1.ItemArray)
                            {
                                row += "\t" + column;
                            }
                            Console.WriteLine("{0}", row);
                        }
                        Console.WriteLine(System.Environment.NewLine);
                    }
                    // Print out table relations  
                    foreach (DataRelation relation in myDataSet.Relations)
                    {
                        Console.WriteLine("RELATION: {0}", relation.RelationName);
                        Console.WriteLine("--------------------------------------");
                        Console.WriteLine("Parent: {0}", relation.ParentTable.TableName);
                        Console.WriteLine("Child: {0}", relation.ChildTable.TableName);
                        Console.WriteLine(System.Environment.NewLine);
                    }
                    Console.ReadKey();
                }
            }
            catch (Exception ex1)
            {
                Console.WriteLine(ex1.Message);
            }
        }
    }
}