<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication3._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br />
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList><br />
<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
</div>
</form>
</body>
</html>
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
namespace WebApplication3
{
public partial class _Default : System.Web.UI.Page
{
protected void Button1_Click(object sender, EventArgs e)
{
DropDownList1.Items.Add(TextBox1.Text);
DropDownList1.Visible = true;
TextBox1.Visible = false;
}
protected void Page_Load(object sender, EventArgs e)
{
DropDownList1.Visible = false;
}
}
}