CustomValidator in C# not picking up colour

Question

I'm trying to use CustomValidator on a drop down list within my webpage, and it isn't being triggered correctly on form submit as the colour of the dropdown doesn't change. I've got the same validation working on text boxes just fine, but I'm obviously doing something wrong for drop downs and would appreciate any help!

I used this Change Text Box Color using Required Field Validator. No Extender Controls Please

And I think what's happening is that the validation is triggered on the form submit. The logic in the .cs file and the javascript file is the same, so that if javascript is disabled by the user the validation should still kick in.

The first value in the dropdown is "Select a value" so my validation says as long as it's not that value proceed.

.aspx file

<p class="form-row">
        <asp:DropDownList ID="valueDropDown" runat="server"  CssClass="tablet" ></asp:DropDownList>
        <asp:CustomValidator ID="CustomValidator4" runat="server" ErrorMessage=""
            ControlToValidate="valueDropDown" ClientValidationFunction="ValidateDD"
            OnServerValidate="CustomValidator4_ServerValidate"
            ValidateEmptyText="True" >
        </asp:CustomValidator>
 </p>

.cs file

 protected void CustomValidator4_ServerValidate(object source, ServerValidateEventArgs args)
        {
            bool is_valid = valueDropDown.Text != "Select a value";
            valueDropDown.BackColor = is_valid ? Color.White : Color.Red;
            args.IsValid = is_valid;
        }

Javascript

function ValidateDD(source, args) {
    var is_valid = $("#valueDropDown").val() != "Select a value";
    $("#valueDropDown").css("background-color", is_valid ? "white" : "#EEB4B4"); 
    args.IsValid = is_valid;
}

Any help would be appreciated - I'm really stuck as to why this isn't working!

EDIT

Ok following on from what @Gian-Paolo has said I've now removed the first required validator from my code but I'm still getting the same problem. The colour is still not being applied.

This has now been removed:

<asp:RequiredFieldValidator ID="ValidatorDD" ControlToValidate="valueDropDown" runat="server" InitialValue="-1" Text="* Please select a value" ErrorMessage="" CssClass="error" Display="Dynamic" ></asp:RequiredFieldValidator>

score 1 · Accepted Answer · answered Nov 19 '15 at 11:47

1

You are attaching to the same valueDropDown control 2 validators:

<asp:RequiredFieldValidator ID="ValidatorDD" ControlToValidate="valueDropDown"... >
</asp:RequiredFieldValidator>
<asp:DropDownList ID="valueDropDown" runat="server"  CssClass="tablet" >
</asp:DropDownList>
<asp:CustomValidator ID="CustomValidator4" ...
        ControlToValidate="valueDropDown" ClientValidationFunction="ValidateDD"...>
</asp:CustomValidator>

I assume javascript will run first validator code, and since that return false stop evaluating the following ones. Same for Server code if JS is disabled in the browser. Try to remove the requiredFieldValidator.

Also, refine your question: what do you mean with " (my customavlidator) isn't being picked up"? (just realized now that I'm not sure I understood your question)

answered Nov 19 '15 at 11:47

Gian Paolo

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Thanks for your answer. I've now removed the required field validator and unfortunately the same thing is still happening. I've updated my question to reflect that. – hlh3406 Nov 19 '15 at 11:57
Do you mean mean that your `CustomValidator4_ServerValidate` is not called at all? Are you sure that `valueDropDown.Text` is exactly "Select a value". Try to debug it! – Gian Paolo Nov 19 '15 at 12:02
I cleaned my solution and did a rebuild and it started to work once I'd removed the required field validator. Thanks for your help! – hlh3406 Nov 19 '15 at 12:12

CustomValidator in C# not picking up colour

1 Answers1