[C#] Viết ứng dụng Auto Fill list Textbox from clipboard Winform

Video demo ứng dụng:

Full source code C#:

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



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

            foreach (Control control in panel1.Controls)
            {
                if (control is TextBox)
                {                   
                    TextBox textBox = (TextBox)control;
                    textBox.KeyDown += TextBox_KeyDown;
                    textBox.KeyPress += TextBox_KeyPress;
                }
            }
        }

        private void TextBox_KeyPress(object sender, KeyPressEventArgs e)
        {
            // chỉ cho phép nhập số
            if (!char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar))
            {                
                e.Handled = true;
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void TextBox_KeyDown(object sender, KeyEventArgs e)
        {
           
            if (e.Control && e.KeyCode == Keys.V)
            {               
                HandlePasteEvent((TextBox)sender);
            }
        }

        private void HandlePasteEvent(TextBox textBox)
        {
           
            if (Clipboard.ContainsText())
            {
                string clipboardText = Clipboard.GetText().Trim().Replace(" ","");
                var regex = new Regex(@"^\d{12}$");
                if (clipboardText.Length == 12 && regex.IsMatch(clipboardText))
                {
                    char[] characters = clipboardText.ToCharArray();

                    foreach (Control control in panel1.Controls)
                    {
                        if (control is TextBox)
                        {
                            var nameControl = control.Name;
                            var i = Convert.ToInt16(nameControl.Split('_').LastOrDefault()) - 1;
                            control.Text = characters[i].ToString();
                        }
                    }
                }
            }
        }

    }
}