Textbox and dynamic C# + ASP.NET button

Question

I am feeding a webform with textboxes and buttons from a Repeater, according to the tuples(table people) returned in an SQL query, linking the code to specific attributes within these controls. For textboxes I am using the Hidden attribute, while for buttons I am using the Commandargument attribute in order to use it with the Oncommand method. Now I need the Oncommand method to identify which textbox(Hidden attribute) corresponds to the linked Commandargument so that I can enter the information in my database. Is there any way to do this check or even an easier way to achieve my goal?

My Repeater:

<div class="col-md-6" runat="server">
     <asp:Repeater ID="rptControles" runat="server">
          <ItemTemplate>
               <div class="row">
                    <div class="col-md-12">
                         <div class="form-group">
                              <div id="formulario" class="input-group" runat="server">
                                   <asp:TextBox ID="txtURL" class="form-control" hidden='<%# DataBinder.Eval(Container.DataItem, "pes_codigo") %>' placeholder='<%# DataBinder.Eval(Container.DataItem, "pes_nome") %>' runat="server"></asp:TextBox>
                                   <span class="input-group-btn">
                                        <asp:Button ID="btnValidar" CommandArgument='<%# DataBinder.Eval(Container.DataItem, "pes_codigo") %>' OnCommand="btnValidar_Command" CssClass="btn btn-default" runat="server" Text="Go!" CausesValidation="false" />
                                   </span>
                              </div>
                         </div>
                    </div>
               </div>
          </ItemTemplate>
     </asp:Repeater>
 </div>

Page_load:

protected void Page_Load(object sender, EventArgs e)
{
    populaFormulario(Convert.ToInt32(Session["codigo_evento"]));
}

populaFormulario:

public void populaFormulario(int codigoEvento)
{
    ParticipanteDB parDB = new ParticipanteDB();

    rptControles.DataSource = parDB.SelecionarParticipantes(codigoEvento).Tables[0].DefaultView;
    rptControles.DataBind();
}

btnValidar_Command:

protected void btnValidar_Command(object sender, CommandEventArgs e)
{
    var button = (Button)sender;

    var textbox = (TextBox)button.Parent.FindControl("txtURL");

    TextBox1.Text = e.CommandArgument.ToString() + " - " + textbox.Text;
}

Example of return of textboxes and Buttons:

Answer 1

Since your Commandargument has the same value as the Hidden attribute of the textbox, take advantage of and use Commandargument itself, which is sent in Commandeventargs.

EDIT : Since you want the Textbox value for the button, you can then use the Parent property of the Sender (in your case). The Parent will be your div form. Once accessing this div, we use the Findcontrol method to search for a control called txtUrl. Remembering to make the proper Casts, follows below the example :

   using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Linq;
    using System.Web;
    using System.Web.UI;
    using System.Web.UI.WebControls;

    namespace WebApplication3
    {
        public partial class _Default : Page
        {
            protected void Page_Load(object sender, EventArgs e)
            {
#region Só um exemplo
                var tabela = new DataTable();
                tabela.Columns.Add(new DataColumn { ColumnName = "pes_codigo" });
                tabela.Columns.Add(new DataColumn { ColumnName = "pes_nome" });

                tabela.Rows.Add("1", "João");
                tabela.Rows.Add("2", "Paulo");
                tabela.Rows.Add("3", "Pedro");
                tabela.Rows.Add("4", "Mateus");

                rptControles.DataSource = tabela;
                rptControles.DataBind();
#endregion
            }

            protected void btnValidar_Command(object sender, CommandEventArgs e)
            {
                var button = (Button)sender;//Pegamos o botão.

                var textbox = (TextBox)button.Parent.FindControl("txtUrl");//button.Parent é a div id= formulário, logo iremos procurar o textbox txtUrl nessa Div.

                Response.Write(textbox.Text);//Pronto, temos o valor do textbox que você quer.
                Response.Write(e.CommandArgument);//Em e.CommandArgument terá o valor de pes_codigo que vem da tabela pessoas.
            }

        }
    }

Note: I only added one CausesValidation="False" on buttons, to avoid problems with validation.