Befüllen und Lesen von DataSets mit DataReader

using System;
using System.Data;
using System.Data.SqlClient;

namespace Chapter5
{

    public class DataTableReaderSample
    {
        public static void Main()
        {
            //----- Daten und Schema laden
            DataSet ds = LoadData();

            //----- Daten ausgeben
            Print(ds);

            //----- Daten als XML Datei speichern
            ds.WriteXml("data.xml");
        }

        static DataSet LoadData()
        {
            IDbConnection con = null;
            try
            {
                //----- Verbindung aufbauen
                con = new SqlConnection("data source=(local)\\SQLEXPRESS; " +
                    " database=NETBOOK; Integrated Security= True;");
                //----- Select-Kommando erzeugen 
                IDbCommand cmd = new SqlCommand();
                cmd.Connection = con;
                cmd.CommandText = "SELECT * FROM Person; SELECT * FROM Contact";
                //----- Verbindung oeffnen 
                con.Open();
                //----- Reader erzeugen 
                IDataReader reader = cmd.ExecuteReader();

                //----- DataSet erzeugen und mit Reader befuellen
                DataSet ds = new DataSet("PersonContacts");
                //ds.Tables.Add(new DataTable("Person"));
                //ds.Tables.Add(new DataTable("Contact"));
                ds.Load(reader, LoadOption.OverwriteChanges, "Person", "Contact");
                // Aenderungen uebernehmen oder verwerfen
                if (ds.HasErrors) ds.RejectChanges(); else ds.AcceptChanges();
                return ds;
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString()); 
                return null;
            }
            finally
            {
                if (con != null) con.Close(); 
            }
        }


        static void Print(DataSet ds)
        {
            DataTableReader r = ds.CreateDataReader();
            int i = 1; 
            do
            {
                Console.WriteLine(" ---- Table " + i + "----------------"); 
                while (r.Read())
                {
                    object[] vals = new object[r.FieldCount];
                    r.GetValues(vals);
                    foreach (object v in vals)
                    {
                        Console.Write(v.ToString() + " - ");
                    }
                    Console.WriteLine();
                }
                i++; 
            } while (r.NextResult()); 
        }

    }

}