ทำให้ array loop check data ใน text file 1000 รอบ ครับ หน้าแสดงผมคือ Form_Load

private void SR_Load(object sender, EventArgs e)
        { 
            string text = "CheckStock.txt";
            StreamReader sr = new StreamReader(text);
            String line = String.Empty;
            int i = 0;
            while ((line = sr.ReadLine()) != null)
            {
                for (i = 0; i <= 1000; i++)
                {
                    array[i] = Convert.ToInt32(line);
                }
            }
            textBox1.Focus();
            textBox3.Text = "0";  
        }
error ตรง  Convert.ToInt32(line);

private List<string> array = new List<string>();
foreach (string s in System.IO.File.ReadAllText(@"F:\TestCSharp\Net Work\Loadwebtoons\Loadwebtoons\TextFile1.txt").Trim())
             {
                 array.Add(s);
             }

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

namespace CheckStock1
{
    public partial class SR : Form
    {
        public string A { get; set; }
        public string B { get; set; }
        public SR(string data,string data2)
        {
            InitializeComponent();
            A = data;
            B = data2;
        }
        private bool Check(string input)
        {
            bool b = false;
            foreach (string s in System.IO.File.OpenText(@"CheckStock.txt").ReadToEnd())
            {
                if(s==input)
                {
                    b = true;
                    return b;
                }
            }
            return b;
        }
        private List<string> array = new List<string>();
        private void SR_Load(object sender, EventArgs e)
        {

            //string log = "CheckStock.txt";
            //StreamReader sr = new StreamReader(log);
            //string line = string.Empty;
            //int i = 0;
            //while((line = sr.ReadLine()) != null)
            //{  
            //        array.Add(line);   
            //}
            

            //string text = "CheckStock.txt";
            //StreamReader sr = new StreamReader(text);
            //String line = String.Empty;
            //while ((line = sr.ReadLine()) != null)
            //{
            //    for (int i = 0; i <= 1000; i++)
            //    {
            //        array[i] = Convert.ToInt32(line);
            //    }
            //}

            //foreach (string s in System.IO.File.ReadAllText(@"CheckStock.txt"))
            //{
            //    array.Add(s);
            //}
            textBox1.Focus();
            textBox3.Text = "0";  
        }
        private FileInfo f;
        private void button1_Click_1(object sender, EventArgs e)
        {
            Menu m1 = new Menu();
            m1.Show();
            this.Hide();
        }
        
        string C = DateTime.Now.ToString("dd/MM/yyyy");
        private void textBox1_KeyDown_1(object sender,KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                if (textBox1.Text.Length >= 15 || textBox1.Text.Length < 5)
                {
                    MessageBox.Show("Number Invalid");
                    textBox1.Text = "";
                    return;
                }
                string str = ((TextBox) sender).Text;
                if (!array.Contains(str))
                {
                    array.Add(str);
                    int Number = Convert.ToInt32(textBox3.Text.ToString());
                    string nb = (++Number).ToString();
                    textBox3.Text = nb;
                    textBox2.Text = textBox1.Text.Substring(0, 4);
                    label5.Text = textBox1.Text;
                    string log = "CheckStock.txt";
                    this.textBox1.Multiline = true;
                    if (File.Exists(log) == true)
                    {
                        f = new FileInfo(log);
                        StreamWriter sw = f.AppendText();
                        sw.WriteLine(C + "\t" + A + "\t" + B + "\t" + textBox1.Text + "\t" + textBox2.Text + "\t" + "1");
                        textBox1.Text = "";
                        sw.Close();
                    }
                    else if (File.Exists(log) == false)
                    {
                        f = new FileInfo(log);
                        StreamWriter sw = f.CreateText();
                        sw.WriteLine(C + "\t" + A + "\t" + B + "\t" + textBox1.Text + "\t" + textBox2.Text + "\t" + "1");
                        textBox1.Text = "";
                        sw.Close();
                    }
                }
                else
                {
                    MessageBox.Show("Scan Again");
                    textBox1.Text = "";
                    return;
                }                
            }         
        }
        }
    }

private bool Check(string input)
        {
              string log = "CheckStock.txt";
              StreamReader sr = new StreamReader(log);
              string line;
              bool b = false;
              //foreach (string s in System.IO.File.OpenText(@"CheckStock.txt").ReadToEnd())
              while((line = sr.ReadLine())!=null)
              {
                  if (line == input)
                  {
                      b = true;
                      return b;
                  }
              }
              return b;
        }

private void textBox1_KeyDown_1(object sender,KeyEventArgs e)

string str = ((TextBox) sender).Text;
if(!Check(str))
{
  using (StreamWriter sw =!System.IO.File.Exists(@"TextFile1.txt")? System.IO.File.CreateText(@"TextFile1.txt"):new StreamWriter(filelst)) { sw.WriteLine("5555"); }
}

private bool Check(string input)

private void SR_Load(object sender, EventArgs e)
        {
            textBox1.Focus();
            textBox3.Text = "0";  
           int d = DateTime.Now.Second;
            bool b = Check("Test");
            MessageBox.Show("Check  " +  DateTime.Now.Second - d + "Second");
        }