Purvi's Blog: How To Use RequiredFieldValidator control with DropDownList control For Validation

Monday, 4 March 2013

How To Use RequiredFieldValidator control with DropDownList control For Validation

How To Use RequiredFieldValidator control with DropDownList control For Validation
http://www.dotnetpools.com/Article/ArticleDetiail/?articleId=252&title=How-To-Use-RequiredFieldValidator-control-with-DropDownList-control-For-Validation

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm7.aspx.cs" Inherits="WebApplication1.WebForm7" %>

<!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></title>
</head>
<body>
    <form id="form1" runat="server">

    <div>
       <asp:DropDownList ID="DropDownList1" runat="server" Width="200px">
    </asp:DropDownList><asp:RequiredFieldValidator ID="RequiredFieldValidator1" ControlToValidate="DropDownList1" runat="server" ErrorMessage="Please select item."></asp:RequiredFieldValidator>
    </div>
    <br />
    <asp:button runat="server" text="Submit" onclick="Unnamed1_Click" />
    <br />
    <asp:Label ID="Label1" runat="server" style="color: #FF3300" Text=""></asp:Label>
    </form>
</body>
</html>

Now in your .cs page add the below code .

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

namespace WebApplication1
{
    public partial class WebForm7 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                DropDownList1.Items.Add(new ListItem("Select Item", ""));
                DropDownList1.Items.Add(new ListItem("Item 1", "1"));
                DropDownList1.Items.Add(new ListItem("Item 2", "2"));
                DropDownList1.Items.Add(new ListItem("Item 3", "3"));
                DropDownList1.Items.Add(new ListItem("Item 4", "4"));
                DropDownList1.Items.Add(new ListItem("Item 5", "5"));
            }
        }

        protected void Unnamed1_Click(object sender, EventArgs e)
        {
            Label1.Text = "Page post take place.";
        }
    }
}

Now run the application for checking output.