Hidden field
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Default_aspx" %>
HiddenField Control
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class Default_aspx : System.Web.UI.Page
{
protected void hdnSecretValue_ValueChanged(object sender, EventArgs e)
{
HiddenField hdn = (HiddenField)sender;
lblMessage.Text = "The new value is " + hdn.Value + ".";
}
}