จาก Code ผมจะเอาค่า Array ที่เก็บมาแสดงเฉพาะที่มันซ้ำกัน เช่น 2,3,4,5,5,6,7,8 แล้วผมใส่เลข 5 ลง TextSearch ให้มันแสดงผลออกมาว่า 5 อยู่ TextBox ไหน มีกี่ตัว แบบนี้ทำได้มั้ยครับ รบกวนหน่อยครับ

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;

namespace FirstP
{
    public partial class TestForm : Form
    {
        private bool restart;
        public TestForm()
        {
            InitializeComponent();
        }private void OnlyNumber(object sender,KeyEventArgs e) {

            TextBox tb1 = (TextBox)sender;
            if (restart)
            {
                sender = "";
                restart = false;
            }

            if (!(e.KeyValue == '0'
                || e.KeyValue == '1'
                || e.KeyValue == '2'
                || e.KeyValue == '3'
                || e.KeyValue == '4'
                || e.KeyValue == '5'
                || e.KeyValue == '6'
                || e.KeyValue == '7'
                || e.KeyValue == '8'
                || e.KeyValue == '9'
               ))
            {
                e.SuppressKeyPress = true;
            }
        }

        private void btn1_Click(object sender, EventArgs e)
        {
            string[] str1 = txt1.Text.Split(',');
            int len = str1.Length;

            string[] str2 = txt2.Text.Split(',');
            len = str2.Length;

            string[] str3 = txt3.Text.Split(',');
            len = str3.Length;

            string[] str4 = txt4.Text.Split(',');
             len = str4.Length;

            string[] str5 = txt5.Text.Split(',');
            len = str5.Length;

            string[] str6 = txt6.Text.Split(',');
            len = str6.Length;
            string[] str7 = txt7.Text.Split(',');
             len = str7.Length;

            string[] str8 = txt8.Text.Split(',');
            len = str8.Length;

            string[] str9 = txt9.Text.Split(',');
            len = str9.Length;

            string[] str10 = txt10.Text.Split(',');
            len = str10.Length;
            int[] a = new int[len];
            int[] b = new int[len];
            int[] c = new int[len];
            int[] d = new int[len];
            int[] z = new int[len];
            int[] f = new int[len];
            int[] g = new int[len];
            int[] h = new int[len];
            int[] j = new int[len];
            int[] k = new int[len];
            for (int i = 0; i < len; i++)
            {
                a[i] = Convert.ToInt32(str1[i]);
                b[i] = Convert.ToInt32(str2[i]);
                c[i] = Convert.ToInt32(str3[i]);
                d[i] = Convert.ToInt32(str4[i]);
                z[i] = Convert.ToInt32(str5[i]);
                f[i] = Convert.ToInt32(str6[i]);
                g[i] = Convert.ToInt32(str7[i]);
                h[i] = Convert.ToInt32(str8[i]);
                j[i] = Convert.ToInt32(str9[i]);
                k[i] = Convert.ToInt32(str10[i]);
            }
            string str11 = "";
            for(int i = len - 1; i >= 0; i--)
            {
                str11 = str11 + a[i].ToString() + "," + b[i].ToString() +"," +c[i].ToString()+ ","
                    + d[i].ToString() + "," +z[i].ToString() + "," + f[i].ToString() + ","
                    + g[i].ToString() + "," + h[i].ToString() + "," + j[i].ToString() + ","
                    + k[i].ToString() + ",";
            }
            if (txtSearch.Text == txtSearch.Text) {

                lbl1.Text = txtSearch.Text;

            }
            
           
        }

        private void txt1_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt2_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt3_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt4_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt5_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt6_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt7_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt8_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt9_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txt10_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }

        private void txtSearch_KeyDown(object sender, KeyEventArgs e)
        {
            TextBox tb1 = (TextBox)sender;
            OnlyNumber(sender, e);
        }
    }
    }