In this blog we will know how to validate
blank textbox using CustomValidator in ASP.Net.
<%@
Page Language="C#"
AutoEventWireup="true"
CodeBehind="Default.aspx.cs"
Inherits="Blank__textbox_CustomValidator._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
id="Head1"
runat="server">
<title>Untitled
Page</title>
</head>
<body>
<form id="form1"
runat="server">
<div>
<div>
<asp:Label
ID="lblName"
Text="Name:"
AssociatedControlID="txtName"
runat="server"
/>
<br
/>
<asp:TextBox
ID="txtName"
runat="server"
/>
<asp:CustomValidator
ID="cv_name"
runat="server"
ControlToValidate="txtName"
Text="Name
should not be blank"
ValidateEmptyText="true"
OnServerValidate="cv_name_ServerValidate"></asp:CustomValidator><br
/>
<asp:Button
ID="btnSubmit"
Text="Submit"
runat="server"
/>
</div>
</div>
</form>
</body>
</html>
.CS Code
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
Blank__textbox_CustomValidator
{
public partial
class _Default : System.Web.UI.Page
{
protected void
cv_name_ServerValidate(object source,
ServerValidateEventArgs args)
{
if (args.Value.Length != 0)
args.IsValid
= true;
else
args.IsValid
= false;
}
}
}