namespace WebPart12
{
    [Guid("1dd693c3-4b4f-475d-af03-a0bccadd0523")]
    public class WebPart12 : System.Web.UI.WebControls.WebParts.WebPart
    {
        public WebPart12()
        {
            this.ExportMode = WebPartExportMode.All;
        }

        protected Label lblAutomobile = new Label();
        protected DropDownList ddlAutomobile = new DropDownList();
        protected Button btnConferma = new Button();
        protected override void OnInit(System.EventArgs e)
        {
            base.OnInit(e);

            lblAutomobile.ID = "lblAutomobile";
            lblAutomobile.Text = "Sala";
            Controls.Add(lblAutomobile);

            ddlAutomobile.ID = "ddlAutomobile";
            ddlAutomobile.Load += new EventHandler(ddlAutomobili_Load);
            Controls.Add(ddlAutomobile);
        }

        void ddlAutomobili_Load(object sender, EventArgs e)
        {
            string strQuery = "SELECT auto_id, auto_nome FROM Automobili;";
            SqlConnection connessione = new SqlConnection("Data Source=NomeServer;Initial Catalog=NomeDatabase;Integrated Security=True");
            {
                SqlCommand commando = new SqlCommand(strQuery, connessione);
                connessione.Open();
                SqlDataReader leggi = commando.ExecuteReader();

                try
                {
                    int i = 0;
                    while (leggi.Read())
                    {
                        ddlAutomobile.Items.Insert(i++, new ListItem(leggi["auto_nome"].ToString()));

/*qui sarebbe desiderato fare qualcosa tipo:
ddlAutomobile.Items.Insert(leggi["auto_id"], new ListItem(leggi["auto_nome"].ToString()));
al posto della variabile int i */
                    }
                }
                finally
                {
                    leggi.Close();
                }
            }
        }


        protected override void Render(HtmlTextWriter writer)
        {
            writer.Write("<table><tr><td>");
            lblAutomobile.RenderControl(writer);
            writer.Write("</td></tr><tr><td>");
            ddlAutomobile.RenderControl(writer);
            writer.Write("</td></tr>");
        }
    }
}

void ddlAuto_Load(object sender, EventArgs e)
        {
                try
                {
                    SqlConnection cn = new SqlConnection(this.stringaDiConnessione);
                    SqlCommand cmd = new SqlCommand("select auto_nome from Automobili", cn);
                    SqlDataAdapter adp = new SqlDataAdapter(cmd);
                    DataSet ds = new DataSet();
                    adp.Fill(ds);
                    this.ddlAuto.DataSource = ds.Tables[0].DefalutView;
                    this.ddlAuto.DataBind();
                }
                catch (Exception ex)
                {
                    this.ddlAuto.DataSource = null;
                    this.ddlAuto.DataBind();
                    lblError.Visible = true;
                    lblError.ForeColor = Color.Red;
                    lblError.Text = ex.Message;
                }
        }

void ddlAutomobile_Load(object sender, EventArgs e)
        {
            SqlConnection cn = new SqlConnection(this.stringaDiConnessione);
            SqlCommand cmd = new SqlCommand("select auto_nome from Automobili", cn); //adp.RecordsAffected
            cn.Open();
            SqlDataReader adp = cmd.ExecuteReader();
            try
            {
                ddlAutomobile.Items.Clear();
                int i = 0;
                ddlAutomobile.Items.Insert(i++, new ListItem("Selezionare un'automobile..."));
                while (adp.Read())
                {
                    auto = adp["auto_nome"].ToString();
                    ddlAutomobile.Items.Insert(i++, new ListItem(auto));
                }

            }
            catch (Exception ex)
            {
                lblError.Visible = true;
                lblError.ForeColor = Color.Red;
                lblError.Text = ex.Message;
            }
            finally
            {
                adp.Close();
            }
        }