无法获取动态创建的文本框的ID。有解决方案吗

Question

我无法获取动态生成的文本框的ID。因此，我无法得到他们的价值观。在下面发布我的代码。请帮忙 。

protected void txt_Freq_SelectedIndexChanged(object sender, EventArgs e)
    {

        try

        {

            int rem = Convert.ToInt16(ddl_freq.SelectedItem.Value.ToString());
            Table tbl1 = new Table();
            form1.Controls.Add(tbl1);
            for (i = 1; i <= rem; i++)
            {

                TableRow row = new TableRow();
                TableCell cell = new TableCell();
                TextBox tb = new TextBox();
                tb.ID = "rem" + i.ToString();
                Label lb = new Label();
                CalendarExtender calex = new CalendarExtender();
                calex.ID = "calexRem" + i.ToString();
                calex.TargetControlID = "rem" + i.ToString();
                DropDownList txt_Time_rem = new DropDownList();
                txt_Time_rem.ID = "ddl" + i.ToString();


                for (int hr = 0; hr <= 23; hr++)
                {
                    for (int min = 0; min < 60; min += 15)
                    {
                        if (hr <= 9 && min == 0)
                            txt_Time_rem.Items.Add(new ListItem('0' + hr.ToString() + ':' + '0' + min.ToString()));
                        else if (hr <= 9 && min != 0)
                            txt_Time_rem.Items.Add(new ListItem('0' + hr.ToString() + ':' + min.ToString()));
                        else if (hr > 9 && min == 0)
                            txt_Time_rem.Items.Add(new ListItem(hr.ToString() + ':' + '0' + min.ToString()));
                        else
                            txt_Time_rem.Items.Add(new ListItem(hr.ToString() + ':' + min.ToString()));
                    }
                }

                txt_Time_rem.Items.Insert(0, new ListItem("Time"));

                lb.Text = "Reminder " + i.ToString();

                cell.Controls.Add(lb);

                 cell.Controls.Add(tb);
                 cell.Controls.Add(calex);
                cell.Controls.Add(txt_Time_rem);



                row.Cells.Add(cell);
                tbl1.Rows.Add(row);
                Response.Write(tb.ID);
            }


        }
        catch (Exception ex)
        {
            Response.Write(ex.Message);
        }


    }

 protected void btntemp_Click(object sender, EventArgs e)
    {
             TextBox tb = new TextBox();
        for(x=1;x<=Convert.ToInt16(ddl_freq.SelectedItem.Value.ToString());x++)
        {
            TextBox txtUserName = form1.FindControl("rem"+x.ToString()) as TextBox;

            if (txtUserName != null)
            {
                Response.Write("ID found!");

            }
            else
            {
                Response.Write("Failed");
            }

我尝试用Page.Master替换form1，因为我有一个母版页，但没有任何作用。它将打印＆＃34;失败＆＃34;。请帮助。