private void button3_Click_1(object sender, EventArgs e)
 {
     try
     {
         BEL.Eleve clt = EleveDAO.Get_client_ID(int.Parse(tbID.Text));
         tbnom.Text     = clt.Nom;
         tbprenom.Text  = clt.Prenom.ToString();
         tbadresse.Text = clt.adresse;
         tbgr.Text      = clt.num_gr.ToString();
         List <BEL.Eleve> L = new List <BEL.Eleve>();
         L.Add(clt);
         grid_clients.DataSource = L;
     }
     catch (Exception)
     {
         if (tbID.Text == "")
         {
             MessageBox.Show("saisir l'id d'éleve");
         }
         else
         {
             MessageBox.Show("Ce éleve n'existe pas");
         }
     }
 }
        public static Eleve Get_client_ID(int id)
        {
            string          requete = String.Format("select * from eleve where Id={0};", id);
            OleDbDataReader rd      = utils.lire(requete);

            BEL.Eleve c = new BEL.Eleve();
            while (rd.Read())
            {
                c.Id      = rd.GetInt32(0);
                c.Nom     = rd.GetString(1);
                c.Prenom  = rd.GetString(2);
                c.adresse = rd.GetString(3);
                c.num_gr  = rd.GetInt32(4);
            }
            utils.Disconnect();
            return(c);
        }
 private void button3_Click(object sender, EventArgs e)
 {
     try
     {
         BEL.Eleve clt = EleveDAO.Get_client_ID(int.Parse(tbID.Text));
         tbnom.Text     = clt.Nom;
         tbprenom.Text  = clt.Prenom;
         tbadresse.Text = clt.adresse;
         tbgr.Text      = clt.num_gr.ToString();
         List <BEL.Eleve> L = new List <BEL.Eleve>();
         L.Add(clt);
         grid_clients.DataSource = L;
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }
 }