how to access control that dynamically added to page with static ClientIDMode

I have a simple page that hase 1 PlaceHolder and 2 Button("add row","get value") and nothing else.when I click on add row button I create a dynamic Table and place some control in it's cell with set ClientIDMoode=static:

private void CreateTableWithSession(bool FirstLoad)
{
    Table tbl;
    int Row;
    if (Session["tbl"]==null)
    {
        tbl = new Table();
    }
    else
    {
        tbl = (Table)Session["tbl"];
    }
    if (FirstLoad == true)
    {
        tbl.Rows.Clear();
    }
    //////////////////////////////////////////////////
    if (Session["Row"] == null)
    {
        Row = 0;
    }
    else
    {
        Row = int.Parse(Session["Row"].ToString());
    }
    if (FirstLoad == true)
    {
        tbl.Rows.Clear();
    }
    //////////////////////////////////////////////////

    TableRow tr1 = new TableRow();
    TableCell tc = new TableCell();

    TextBox txtBoxUserName = new TextBox();
    txtBoxUserName.ClientIDMode = System.Web.UI.ClientIDMode.Static;
    txtBoxUserName.Text = "0";
    Col++;
    txtBoxUserN开发者_如何转开发ame.ID = "RowNo" + Row.ToString() + "ColumnNo" + Col.ToString();
    tc.Controls.Add(txtBoxUserName);
    tc.Width = 200;
    tc.VerticalAlign = VerticalAlign.Middle;
    tc.HorizontalAlign = HorizontalAlign.Center;
    tr1.Cells.Add(tc);

    tc = new TableCell();
    TextBox txtBoxPassword = new TextBox();
    txtBoxPassword.ClientIDMode = System.Web.UI.ClientIDMode.Static;
    txtBoxPassword.Text = "0";
    Col++;
    txtBoxPassword.ID = "RowNo" + Row.ToString() + "ColumnNo" + Col.ToString();
    tc.Controls.Add(txtBoxPassword);
    tc.Width = 200;
    tc.VerticalAlign = VerticalAlign.Middle;
    tc.HorizontalAlign = HorizontalAlign.Center;
    tr1.Cells.Add(tc);

    tbl.Rows.Add(tr1);

    Session["tbl"] = tbl;

    PlaceHolder1.Controls.Add(tbl);
}

and I want when user clicks on "get value" button ,get 2 textbox values(that dynamically added).but every time it returns Null.

TextBox txtBoxUserName = this.FindControl("RowNo1ColumnNo1") as TextBox;

how I can fix this and access to textbox values?

thanks

Dynamically created controls should be recreated before you can access and I am sure you are not creating the controls when you hit Get Value button. Something will work for you...

protected void AddRow_Click(object sender, EventArgs e)
{
   CreateTableWithSession()
   ...................
}

protected void GetValue_Click(object sender, EventArgs e)
{
   CreateTableWithSession()
   TextBox txtBoxUserName = this.FindControl("RowNo1ColumnNo1") as TextBox;
   ........................
}