how to get textbox value in placeholder on code behind?

Question

I created some textbox and I want to get their value dynamically. Briefly, ı explain my page:

I have dropDown list has number 1 to 15.When the user select number and I

Answer 1

Problem

If you dynamically add controls to a page, you need to reloaded them on Page Init or Page Load.

Otherwise, you won't be able to find them when you post back.

ASPX

Code Behind

private int Total
{
    get
    {
        int total;
        if (Int32.TryParse(ddlUserSelected.SelectedItem.Text, out total)) 
            return total;
        return 0;
    }
}

protected void Page_Load(object sender, EventArgs e)
{
    CreateTextBoxes(Total);
}

protected void ddlUserSelected_SelectedIndexChanged(object sender, EventArgs e)
{
    CreateTextBoxes(Total);
}

protected void btnSave_Click(object sender, EventArgs e)
{
    int total = Total;
    for (int a = 1; a <= total; a++)
    {
        var textbox = PlaceHolder1.FindControl("txtDate" + a) as TextBox;
    }
}

private void CreateTextBoxes(int total)
{
    for (int a = 1; a <= total; a++)
    {
        // Make sure we do not add same ID again
        if (PlaceHolder1.FindControl("txtDate" + a) == null)
        {
            TextBox txtDate = new TextBox();
            Label lbl = new Label();
            lbl.Text = "
";
            txtDate.Width = 70;
            txtDate.CssClass = "tbl";
            txtDate.ID = "txtDate" + a;
            PlaceHolder1.Controls.Add(txtDate);
            PlaceHolder1.Controls.Add(lbl);
        }
    }
}