ASP.NET OnClientClick="return false;" doesn't work

Question

I just want to add some client side (JQuery Javascript) validation in a web user control. I put an OnClientClick handler and the function gets called. BUT, even if I return "false", the OnClick method always get fired. What am I doing wrong ?

I'm with VS 2010, targeting the 4.0 framework with JQuery 1.4.2. and JQuery UI 1.8.4.

Here's a sample code :

<td style="text-align:right"><asp:Button ID="btnAddSave" OnClientClick="return ValidateMail();" OnClick="btnAddSave_Click" runat="server" Text="Submit" /></td>

Script method :

function ValidateMail() {
alert("Bouton clicked");
return false;

}

If I put a breakpoint in the Page_Load event, I see that I get in and the btnAddSave_Click event is also executed.

Have you tried without the alert box? I've read another post like this recently — GôTô, Oct 08 '10 at 20:12
When you view the rendered source of the HTML page, is your "onclick" event rendered in the tag or are you overwriting that in the code behind? Also, do you have any other JQuery events that bind to this control which might be intercepting the call? — Steven Raines, Oct 11 '10 at 20:08

score 12 · Answer 1 · answered Sep 05 '12 at 08:54

12

for some reason, although I didn't have any jquery event handlers attached, it didn't work.

What actually worked was:

OnClientClick="if (validate_form() == false) return(false);"

answered Sep 05 '12 at 08:54

Yaron

1,434
2
19
30

1

You could also write OnClientClick="return validate_form()" – hasi05 Apr 08 '19 at 13:53

score 7 · Accepted Answer · edited May 23 '17 at 11:46

7

Do you have a click event handler (registered via jquery) which returns true? In that case, the return value of OnClientClick is ignored.

Have a look at my question (and answer): Why doesn't returning false from OnClientClick cancel the postback

edited May 23 '17 at 11:46

Community

1
1

answered Jul 25 '11 at 06:23

M4N

90,223
44
210
255

score 3 · Answer 3 · answered Apr 11 '13 at 14:54

3

Great answers. I do it this way. Same result- the OnClick event is not fired off if false is returned from Java function.

OnClientClick = "if (!ValidateDelete()) return false;"
OnClick="btnDeleteSupplier_Click"

answered Apr 11 '13 at 14:54

Bill Pepitone

31
1

score 3 · Answer 4 · answered Jun 17 '11 at 18:15

3

Try changing it to

OnClientClick="ValidateMail(); return false;"

answered Jun 17 '11 at 18:15

alonso.torres

1,129
2
12
26

Thanks for the answer, it works - but this makes no sense! 3 Months prior I had fixed this very same issue with Firefox (before their last release) and it worked with "return ValidateMail();". – Dane Balia Sep 06 '12 at 07:51
1

@alonso.torres I don't understand this. Doesn't that just return false "always" i.e even if the form passes validation it will now return as invalid regardless therefore OnClick will never be fired? – rism Jun 05 '13 at 03:32

score 1 · Answer 5 · answered Apr 17 '20 at 22:12

1

oddly enough this worked for me:

OnClientClick="javascript:SubmitTableData(); return CanSubmit();"

set the return value submit with the first function call:

function CanSubmit() {    
    return submit;
}

Hope this helps someone.

answered Apr 17 '20 at 22:12

SparrowEatsHawk

31
1
4

LukaszBalazy · Answer 6 · 2017-04-05T13:18:18.820

I'm writing this answer only because I'm using html buttons with ASP.NET WebForms and I couldn't find solution why should I replace my piece of code with working examples. Here is solution why it is not working. Hope it will help you to understand the issue like checking it helped me. This is my first post, so sorry for style.

<button type="button" id="buttonAddOrEdit" class="btn btn-success"  runat="server" onclick="return myValidate()"    onserverclick="buttonAddOrEdit_ServerClick">Zapisz</button>

And javascript function:

function myValidation() {
        if (validator.form()) {
           //Project logic
            return true;
        }
        else return false;
    };

Using client side click after correct validation wasn't triggering event on server side that was binded to button. Solution mentioned to change piece of code to:

onclick="if(!myValidation()) return;"

Works because of way that html rendered on page with onserverclick is created. Onserverclick on html button is being replaced by __doPostBack method from javascript. Fullcode of html button rendered on client side looks this way:

<button onclick="return myValidation(); __doPostBack('ctl00$PortalContent$buttonAddOrEdit','')" id="ctl00_PortalContent_buttonAddOrEdit" type="button" class="btn btn-success">Zapisz</button>  Błąd składni

And after replacing it with if statment.

<button onclick="if(!myValidation()) return; __doPostBack('ctl00$PortalContent$buttonAddOrEdit','')" id="ctl00_PortalContent_buttonAddOrEdit" type="button" class="btn btn-success">Zapisz</button>

Working with return myValidate(); won't tirgger event because it returns before __doPostBack.

Following code will allow you to add some another code to button if neccessary and won't cause any issues.

score 0 · Answer 7 · edited Apr 06 '17 at 15:50

0

Just add javascript:

Example:

javascript:return ValidateMail();

edited Apr 06 '17 at 15:50

FelixSFD

5,456
10
40
106

answered Apr 06 '17 at 15:47

pao

1

1

Welcome to Stack Overflow! Stack Overflow [requires that all posts be in English](https://stackoverflow.blog/2009/07/non-english-question-policy/). I've removed the non-english part of your post to comply with this rule. You may also use one of these language specific Stack Overflow communities which allow non-English: [Spanish](http://es.stackoverflow.com), [Japanese](http://ja.stackoverflow.com), [Russian](http://ru.stackoverflow.com), [Portuguese](http://pt.stackoverflow.com). – FelixSFD Apr 06 '17 at 15:50

ASP.NET OnClientClick="return false;" doesn't work

7 Answers7

Linked