how to dynamically generate asp controls from code behind

On my form I want to display n number of rows of asp textboxes where n is determined by the number of records in the corresponding database table. I can dynamically generate html controls and get the values via request.form but I can't figure out how to do the same with asp controls.
The output from the following code, displays the text boxes from the "input type=text" statement, but displays nothing for the "asp:textbox" statement. I would prefer to use asp (or third party controls) so would greatly appreciate help on how to render non-html controls dynamically from my code behind. Thanks.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        Dim ncount As Integer = 0
        Dim strOutput As String = ""
        If Not (Page.IsPostBack) Then
  &n ...