Use asp:RequiredFieldValidator to check the input of an asp:TextBox (VB.net) : RequiredFieldValidator « Validation « ASP.NET Tutorial






  1. ASP.NET Tutorial
  2. Validation
  3. RequiredFieldValidator
<%@ Page Language="VB" %>

<script runat="server">
   sub Submit(Sender as Object, e as EventArgs)
      if Page.IsValid then
         lblMessage.Text = "You passed validation!"
      end if   
   end sub
</script>

<html>
<body>
   <form runat="server">
      <asp:Label id="lblMessage" runat="server" />
      Enter your name:
      <asp:TextBox id="tbFName" runat="server" /><br>
      <asp:RequiredFieldValidator runat="server" ControlToValidate="tbFName" ErrorMessage="First name required"/>

      <asp:Button id="tbSubmit" runat="server" Text="Submit" OnClick="Submit" />
   </form>
</body>
</html>








8.11.RequiredFieldValidator
8.11.1.RequiredFieldValidator requires a user to enter a value into a form field before submitting the form.
8.11.2.Use asp:RequiredFieldValidator to check the input of an asp:TextBox (VB.net)
8.11.3.Use the RequiredFieldValidator's InitialValue to set a default value
8.11.4.Specify ErrorMessage for asp:RequiredFieldValidator
8.11.5.asp:RequiredFieldValidator will be converted to JavaScript Code after loading in client side
8.11.6.A simple use of the RequiredFieldValidator server control (C#)
8.11.7.Text field of RequiredFieldValidator server control (VB)
8.11.8.Placing values between nodes
8.11.9.Working with the InitialValue property
8.11.10.Using two RequiredFieldValidator controls for one form element
8.11.11.Validating Drop-Down Lists with the RequiredFieldValidator Control
8.11.12.Using images for error notifications
8.11.13.Disabling client-side validations in a validation control
8.11.14.Using sound for error notifications
8.11.15.EnableClientScript=false, Display=Static
8.11.16.RequiredFieldValidator for login page
8.11.17.RequiredFieldValidator with server side validation
8.11.18.Hard code error message
8.11.19.RequiredFieldValidator Dynamic Display