C# listy

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {

            int ILE;
            Random r = new Random();

            lista1.Items.Clear();


            ILE = r.Next(5, 20);

            for (int i = 0; i < ILE; i++)
            {
                lista1.Items.Add(r.Next(100));
            }




        }

        private void button2_Click(object sender, EventArgs e)
        {

            int min = Convert.ToInt32((lista1.Items[0]));
            int lenght = lista1.Items.Count;

            for (int i = 0; i < lenght; i++)
            {

              int value = Convert.ToInt32(lista1.Items[i]);


              if (value < min)
              {
                  min = value;

              }

            }
            lista1.SelectedItem = min;










        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                string linia;
                lista1.Items.Clear();
                FileInfo plik = new FileInfo(openFileDialog1.FileName);

                StreamReader p = plik.OpenText();

                while((linia = p.ReadLine()) != null){

                    lista1.Items.Add(linia);

                }
            }
        }

        private void openFileDialog1_FileOk(object sender, CancelEventArgs e)
        {

        }
    }
}