help and idea about code snippet

Hello Friend,

I found your code very interesting. 

For solving your problem use return sender; // return ozellikler;

One small suggestion: instead of the following method signature..
public static List<object> SetListData(string procname, object sender)

use this one
private void Form1_Load(object sender, EventArgs e)
        {
            List iller = SetListData("sp_listil");//il is a class that has properties id,name
        }

        public static List SetListData(string procname)
        {
            T sender = Activator.CreateInstance();
            Type tip = sender.GetType();
            System.Reflection.PropertyInfo[] ozellikler = tip.GetProperties();


            SqlDataReader reader = null;
            List liste = new List();
            while (reader.HasRows && reader.Read())
            {
                CreateSenderObject(sender, reader);
                liste.Add(sender);

            }
            return liste;
        }

        static object CreateSenderObject(object sender, IDataRecord rd)
        {
            Type tip = sender.GetType();
            System.Reflection.PropertyInfo[] ozellikler = tip.GetProperties();
            for (int i = 0; i < ozellikler.Length; i++)
            {
                if (ozellikler[i].PropertyType.ToString() == "System.String")
                    ozellikler[i].SetValue(sender, rd[i].ToString(), null);
                else if (ozellikler[i].PropertyType.ToString() == "System.Int32")
                    ozellikler[i].SetValue(sender, Convert.ToInt32(rd[i].ToString()), null);
                else if (ozellikler[i].PropertyType.ToString() == "System.DateTime")
                    ozellikler[i].SetValue(sender, Convert.ToDateTime(rd[i].ToString()), null);
                else if (ozellikler[i].PropertyType.ToString() == "System.Decimal")
                    ozellikler[i].SetValue(sender, Convert.ToDecimal(rd[i].ToString()), null);
                else if (ozellikler[i].PropertyType.ToString() == "System.Int32")
                    ozellikler[i].SetValue(sender, Convert.ToInt32(rd[i].ToString()), null);
            }
            return ozellikler;
        }

// Also no need of passing sender as return parameter from the CreateSenderObject method, as you already created sender
// Only reference needs to be passed

Please let us know if any error occurs.. or mark as answer