Recreate Dynamic TextBox

[Christian McMillan]

I have a page that will dynamically create text boxes based on a NumberOfFilesValue and place them in a placeholder. This page might postback a few times as the user changes values on the page. I'm not able to find the placeholder in Pre_Init.


using DataServices_v2.Shared;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace DataServices_v2
{
public partial class test : System.Web.UI.Page
{
protected void Page_PreInit(object sender, EventArgs e)
{
List<string> keys = Request.Form.AllKeys.Where(key => key.Contains("Filename")).ToList();
foreach (string key in keys)
{
AddTextBoxRow tbRow = new AddTextBoxRow();
FilenamePlaceholder.Controls.Add(tbRow.NewRow(key));
}
}

protected void Page_Load(object sender, EventArgs e)
{
//
}

protected void NumberOfFilesValue_TextChanged(object sender, EventArgs e)
{
FilenamePlaceholder.Controls.Clear();
int file_count = Convert.ToInt16(NumberOfFilesValue.Text);
string pre = "Filename ";
for (int i = 1; i <= file_count; i++)
{
string control_text = pre + i.ToString();
AddTextBoxRow tbRow = new AddTextBoxRow();
FilenamePlaceholder.Controls.Add(tbRow.NewRow(control_text));
}
}

protected void BatchSubmit_Click(object sender, EventArgs e)
{

}
}
}


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using DataServices_v2.Mover;

namespace DataServices_v2.Shared
{
public class AddTextBoxRow
{

public HtmlGenericControl NewRow(string ControlText)
{
HtmlGenericControl main_div = new HtmlGenericControl("div"); //main div
main_div.Attributes["class"] = "form-group";

Label l = new Label
{
ID = ControlText.Replace(" ", String.Empty) + "Label",
Text = ControlText,
CssClass = "control-label col-md-2"
};
main_div.Controls.Add(l); //add label to main div

HtmlGenericControl value_div = new HtmlGenericControl("div"); //secondary div
value_div.Attributes["class"] = "col-md-10";

TextBox tb = new TextBox
{
ID = ControlText.Replace(" ",String.Empty) + "Value",
CssClass = "form-control"
};
value_div.Controls.Add(tb);

main_div.Controls.Add(value_div); //add secondary div to main div
return main_div;
}








}
}


<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="test.aspx.cs" Inherits="DataServices_v2.test" %>
<asp:Content ID="Content1" ContentPlaceHolderID="MainContent" runat="server">

<div class="form-group">
<asp:Label ID="NumberOfFilesLabel" runat="server" Text="Number of Files" CssClass="control-label col-md-2" />
<div class="col-md-10">
<asp:TextBox ID="NumberOfFilesValue" runat="server" OnTextChanged="NumberOfFilesValue_TextChanged" AutoPostBack="true" CssClass="form-control" style="width:50px" />
</div>
</div>

<aspanel ID="FilenamePlaceholder" runat="server" />
<hr />
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<asp:Button ID="BatchSubmit" runat="server" Text="Create Files" OnClick="BatchSubmit_Click" CssClass="btn btn-default" />
</div>
</div>


</asp:Content>

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