Aug 9

Written by: Steve Gray
8/9/2010 10:10 AM 

This is not a primer on ASP.NET Validation controls, there are plenty of those out there. This is just my handy little piece of cheat code - it's easier to copy it out of here when I need it...

First, place the ValidationSummary control on the page. We'll have the individual controls display an '*' for error, and the Summary control will show the error text

<asp:ValidationSummary id="valSummary" runat="server"
    HeaderText="Errors:"
    ShowSummary="true" DisplayMode="List" />

This RegularExpressionValidator will make sure that the validate field has one to three numeric characters:

<asp:RegularExpressionValidator runat="server" ID="regexpAge" 
    ControlToValidate="txtReqShipDays"
    ValidationExpression="^\d{1,3}$" 
    ErrorMessage="Req Ship Days must be one to three digits."
    Display="Dynamic" Text="*" />

Other regex expressions to use:

"^\d" - numeric only

This RequiredFieldValidator will be sure that a field is not left empty:

<asp:RequiredFieldValidator runat="server" ID="reqAge" ControlToValidate="txtReqShipDays"
ErrorMessage="Missing Req Ship Days" Text="*" Display="Dynamic" />