Question

I’m working on an ASP.NET web project using VS2010/C#, I have some text boxes which users should enter only numbers in them, how can I prevent users from entering non-numeric, floating point numbers and negative numbers in my text boxes? of course I can check entered numbers in server side code, but I think sending data to server and performing validation will take a huge amount of time, is there a way to prevent users from entering non-numeric values? or at least not sending data to server with incorrect data?

thanks

Answer 1

Simply use some javascript and apply to the text box required, then it will not allow the others except numbers, see the following code part.

 <script language="JavaScript">
function onlyNumbers(evt)
{
    var e = event || evt; // for trans-browser compatibility
    var charCode = e.which || e.keyCode;

    if (charCode > 31 && (charCode < 48 || charCode > 57))
        return false;

    return true;

}
</script>

EDIT:

<asp:textbox id="txtNOD" runat="server" Width="52px" Font-Size="10px" 
 Font-Names="Verdana" Height="16px" Enabled="False" onkeypress="return onlyNumbers();"></asp:textbox>