dobo elalvo

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;

namespace A14
{
    public partial class Program : System.Web.UI.Page
    {
        string targetDirectory;
        List<Klasz> klasa = new List<Klasz>();

        public void FillDatum() {
            String[] Files = Directory.GetFiles(targetDirectory, "*.txt");
            for (int x = 0; x < Files.Length; x++)
            {
                Files[x] = Path.GetFileNameWithoutExtension(Files[x]);
                DropDownList1.DataSource = Files;
                DropDownList1.DataBind();
            }
        }
        public void FillOsztaly()
        {
            using (StreamReader file = new StreamReader(targetDirectory + DropDownList1.SelectedItem + ".txt"))
            {
                string line;
                while ((line = file.ReadLine()) != null)
                {
                    Klasz obj = new Klasz();
                    string[] lineArray = line.Split('|').Select(item => item.Trim()).ToArray();
                    obj.Ido = lineArray[0];
                    obj.Cim = lineArray[1];
                    obj.Tipus = lineArray[2];
                    obj.Kep = lineArray[3];
                    klasa.Add(obj);
                }
            }
        }
        public void FillDD2()
        {
            List<string> DDTIpus = new List<string>();
            using (StreamReader file = new StreamReader(targetDirectory + DropDownList1.SelectedItem + ".txt"))
            {
                string line;
                while ((line = file.ReadLine()) != null)
                {
                    Klasz obj = new Klasz();
                    string[] lineArray = line.Split('|').Select(item => item.Trim()).ToArray();
                    obj.Tipus = lineArray[2];
                    DDTIpus.Add(obj.Tipus);
                }
            }
            DropDownList2.DataSource = DDTIpus.Distinct();
            DropDownList2.DataBind();
        }

        protected void Page_Load(object sender, EventArgs e)
        {
            targetDirectory = Server.MapPath("~/Text/");
            if (!IsPostBack)
            {
                FillDatum();
                FillDD2();
            }
        }

        protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
        {
            FillDD2();
        }

        protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            List<Klasz> eredmeny = klasa;
            if (DropDownList1.SelectedIndex > -1)
            {
                FillOsztaly();
                if (DropDownList2.SelectedIndex > -1)
                {
                    eredmeny = eredmeny.FindAll(i => i.Tipus.Contains(DropDownList2.SelectedItem.ToString()));
                }
            }
            GridView1.DataSource = eredmeny;
            GridView1.DataBind();
        }
    }
}