Question

I’ve faced the following problem with my aps validator. I have a textbox with asp validator. When the user leaves the textbox empty and click on the submit button the validation message shows, but the page does a postback. Any ideas what may cause this happen?

Heres the validator:

<asp:RequiredFieldValidator ID="valReqName" runat="server" 
    ControlToValidate="txtName" Display="Dynamic" ErrorMessage="blq blq">
</asp:RequiredFieldValidator>

<asp:TextBox ID="txtName" style="font-family:Tahoma, Geneva, sans-serif; 
    color: #4F4F4F;" runat="server">
</asp:TextBox>

Many thanks,
Anton

EDIT

I have two tabs in an UpdatePanel. The validation problem is part of the second tab, where the user makes some inputs. When I’ve remove this trigger:

<asp:AsyncPostBackTrigger ControlID="lnkUpload" EventName="Click" />

The postback problem was solved, but another problem occurred. Well at least the postback is removed. Thanks for all answers.

(lnkUpload is the id of the second tab linkbutton)

EDIT 2

Well here is the solution. It appears that my problem was the same like in this article. http://jeffreypaarhuis.com/2011/08/08/validation-not-working-in-updatepanel/

Answer 1

I’m posting the solution as it might be useful for someone else.

“This is the problem:
When a validator is loaded on the page it creates a bit of javascript to support the clientside validation. When you place a validator inside an usercontrol that isn´t visible by default, and this usercontrol is in an updatepanel, it does not create that javascript properly.
This is the solution:
Outside the updatepanel, I did above, create a dummy validator with a dummy textbox using a dummy validationgroup like so:“

<%--dummy validator to make ajax validation possible--%>
<asp:RequiredFieldValidator runat="server" CssClass="hidden" ControlToValidate="dummyTextBox" ValidationGroup="dummy"></asp:RequiredFieldValidator>
<asp:TextBox runat="server" ID="dummyTextBox" CssClass="hidden"></asp:TextBox>

It appears that my problem was the same like in this article.