ASP.net button onserverclick only works when onclick isn't defined

Question

    protected void btnNext_Click(object sender, EventArgs e)
    {
        btnNext.InnerHtml = "CLICK";
    }

    <button type="submit" runat="server" onserverclick="btnNext_Click" id="btnNext">Next &gt;</button>

This works fine, but when I add an onclick event:

<button type="submit" runat="server" onserverclick="btnNext_Click" onclick="return checkForm();" id="btnNext">Next &gt;</button>

And in the head:

<script type="text/javascript">

    function checkForm() {

        if (document.getElementById("<%=lstChooseSpec.ClientID %>").value) {
            return true;
        } else {
            $.jGrowl("<strong>Warning!</strong><br />Please select an item", { sticky: true });
            return false;
        }
    }
</script>

It submits the form, but doesn't change the buttons text to 'CLICK'. The text only changes to 'CLICK' when the onclick() isn't defined, although the form is still submitting!

Is there a reason you can't use an instead of a – Becuzz Jan 28 '11 at 15:49 — Becuzz, Jan 28 '11 at 15:49
Note the difference of an HTML – Don Cheadle Nov 07 '19 at 21:47 — Don Cheadle, Nov 07 '19 at 21:47

score 9 · Answer 1 · answered Jan 28 '11 at 21:26

9

try without 'return': <button type="submit" runat="server" onserverclick="btnNext_Click" onclick="checkForm();" id="btnNext">Next ></button>
Or if you wanted checkForm() to control whether to post or not - do like this:

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

answered Jan 28 '11 at 21:26

Roman Asanov

287
2
6

Change the "return" to "return false" and it worked for me. Thank you. – Carter Medlin Jan 20 '16 at 17:21

score 8 · Accepted Answer · answered Jan 28 '11 at 16:16

8

The reason you're seeing this is because when you have both on a button it runs your on click handler followed by the __doPostBack function so the onclick would look something like this

onclick="return checkForm(); __doPostBack('btnNext','')

So as you can see the __doPostBack, which actually sets up which server function to call, is never called. However, since the button is of type submit, the form is still sent back to the server.

answered Jan 28 '11 at 16:16

Vadim

17,897
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1

Note the difference of an HTML – Don Cheadle Nov 07 '19 at 21:50

score 0 · Answer 3 · edited Sep 03 '15 at 15:32

0

Try this:

onclick="javascript:if (!validaForm()) return false;"

It worked for me.

edited Sep 03 '15 at 15:32

josliber

43,891
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answered Sep 03 '15 at 13:45

Ricardo Gaefke

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score 0 · Answer 4 · edited Aug 02 '18 at 12:58

0

Front End

  <button  id="submit1" runat="server"  
              onclick="if(confirm('Sure?')) { } else{ return false} ;"                       onserverclick="submit_ServerClick"  >save</button>

Back End

 protected void submit_ServerClick(object sender, EventArgs e)
 {
 }

edited Aug 02 '18 at 12:58

Liam

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answered Jul 25 '18 at 05:50

Willie Cheng

7,679
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score 0 · Answer 5 · answered Jul 25 '18 at 05:56

0

Can you try with LinkButton:

<asp:LinkButton type="submit" runat="server" onserverclick="btnNext_Click" onclick="return checkForm();" id="btnNext">Next &gt;</asp:LinkButton>

answered Jul 25 '18 at 05:56

Gauravsa

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ASP.net button onserverclick only works when onclick isn't defined

5 Answers5

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