ASP.Net มีคำถามเกี่ยวกับ DropDownList และ Textbox ว่ายังไงให้มันสร้างขึ้นเอง

<asp:DropDownList id="DropDownList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
	<asp:ListItem Value="0" Selected="True">- Please select item</asp:ListItem>
	<asp:ListItem Value="1">1</asp:ListItem>
	<asp:ListItem Value="2">2</asp:ListItem>
	<asp:ListItem Value="3">3</asp:ListItem>
	<asp:ListItem Value="4">4</asp:ListItem>
	<asp:ListItem Value="5">5</asp:ListItem>
</asp:DropDownList>

Private Sub DropDownList1_SelectedIndexChanged(sender As Object, e As EventArgs)
	Dim i As Integer
	Dim txtBox As TextBox
	For i = 1 To Cint(DropDownList1.SelectedItem.Value) 
		txtBox = New TextBox
		With txtBox
		    .Text = "My Customer"
		    .Font.Size = "30"
		End With
		Me.pnlMain1.Controls.Add(lblText)
	Next
End Sub

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

namespace Q1_DDL_TX
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            loadDD();
        }

        private void loadDD()
        { 
            var S = 5;
            for (int i = 1; i <= S; i++)
			{
                comboBox1.Items.Add(i);
			}          
        }
        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            //MessageBox.Show(comboBox1.SelectedItem.ToString());
            var s = Convert.ToInt32(comboBox1.SelectedItem.ToString());
            for (int i = 0; i < s; i++)
            {
                TextBox textbox = new TextBox();
                int count = panel1.Controls.OfType<TextBox>().ToList().Count; ;
                textbox.Location = new System.Drawing.Point(60, 25 * count);
                textbox.Size = new System.Drawing.Size(80, 20);
                textbox.Name = "textbox_" + (count + 1);
                textbox.TextChanged += new System.EventHandler(this.TextBox_Changed);
                panel1.Controls.Add(textbox);
                
            }
        }

        private void TextBox_Changed(object sender, EventArgs e)
        {
            throw new NotImplementedException();
        }
    }
}