Validating textbox only if checkbox is checked - no post back

Question

I have a asp.net CheckBox and I have a textbox, I only want textbox to validate when checkbox is checked otherwise just leave it like this.

I find MVC post but I want for asp.net forms Validating textbox only if checkbox is checked using MVC

This is my current code which validates textbox regardless of checkbox is checked or not,

<asp:TextBox ID="txtSubject" runat="server" />
<asp:CheckBox ID="chkSubjectRequired" runat="server" />
<asp:RequiredFieldValidator ID="rfvSubject" ControlToValidate="txtSubject" ErrorMessage="You must enter a subject." runat="server" />

@BhushanKawadkar it's a asp.net required validator, it doesn't have any other code :S — Mathematics, Aug 05 '14 at 09:11
I believe, you just don't need Required Field Validator here, rather just validate through javascript on page submit using OnclientClick event. It will avoid postback also. — Murtaza, Aug 05 '14 at 09:12

score 0 · Accepted Answer · answered Aug 05 '14 at 09:20

You will need a custom validator ,then:

<asp:TextBox ID="txtSubject" runat="server" />
<asp:CustomValidator ControlToValidate="txtSubject" OnServerValidate="IsTextboxValid" Text="Text box is invalid" runat="server"/>

In code behind,define custom validation method:

protected void IsTextboxValid(object sender,ServerValidateEventArgs e)
{
    e.IsValid=chkSubjectRequired.Checked;

}

Please note that this is Server-side Validation

score 0 · Answer 2 · edited May 23 '17 at 11:52

0

this is what you looking for. Just enable/disable the validator (also textbox if you want) that's all.

edited May 23 '17 at 11:52

Community

1
1

answered Aug 05 '14 at 09:23

Onur Topal

3,042
1
24
41

score -1 · Answer 3 · answered Jul 03 '18 at 12:33

-1

Validate The Text Box Only Number :

   <input type="text" onkeydown="ValidateNumber(event);">

    <script>
    function ValidateNumber(e) {
    if ((e.keyCode >= 8 && e.keyCode <= 57) || (e.keyCode >= 96 && e.keyCode <= 105)) {
        return true
    }

    return false;
};

answered Jul 03 '18 at 12:33

Mahaveer Jangid

366
2
11

@NicoHaase i am not getting your question, plz explain – Mahaveer Jangid Aug 06 '18 at 00:56
The OP asked about some validation that should only take place if a checkbox is checked, and your code does not take that into account – Nico Haase Aug 06 '18 at 07:21
If checkbox is checked than this validation should work.. isn’t it..? – Mahaveer Jangid Aug 06 '18 at 07:28
And how does your code check for the status of the checkbox, so how does it skip the validation if the checkbox is not checked? – Nico Haase Aug 06 '18 at 07:31
if(document.getElementById('checkboxid').checked) { Above Code} – Mahaveer Jangid Aug 06 '18 at 12:17
Please do not add code to the comment section. If that should be a part of your answer, edit the answer – Nico Haase Aug 06 '18 at 13:41

Validating textbox only if checkbox is checked - no post back

3 Answers3