ASP CustomValidator, advancing to postback after error

I have an ASP .NET page with ASP validators (Required Field, Regular Expression,...) plus java script functions for a开发者_如何学Godditional validation (for example, to check if second date bigger than first date, among others).

I usually do:

<script type="text/javascript">

    function validate() {
        // ...
        alert('Not valid!');
        return false;
    }    
</script>


<asp:Button ID="Button1" runat="server" Text="Add" 
            OnClientClick="return validate();" OnClick="Button1_Click" />

So, the button advances to the postback if the asp and the javascript validation both pass, and it works fine.

I’m trying out the custom validator:

<asp:CustomValidator ID="CustomValidator1" 
EnableClientScript="true" runat="server" ControlToValidate="TextBox1" 
ClientValidationFunction="validate();" >
</asp:CustomValidator> 

(also tried with ClientValidationFunction="return validate();")

But the page is continuously advancing to the postback, even after showing the “not valid” alert... Any thoughts? Thanks!

When using a CustomValidator, the client side validation function needs to accept a source and an arguments parameter. Then, to mark the validation as failed, you set arguments.IsValid to false. Here is the MSDN page for the CustomValidator.

function validate(source, arguments) {
   // ...

   alert('Not valid!');
   arguments.IsValid=false;
}

like @Jason wrote, when using CustomValidator client is excepting for source and arguments params. a quick sample of use both client and server side with CustomValidator.

CustomValidator use ClientValidationFunction and OnServerValidate properties:

<asp:CustomValidator ID="cvCreditCard"  runat="server" ErrorMessage="Error Message"  ControlToValidate="txtCardNumber" ClientValidationFunction="Validators.CardNumber" OnServerValidate="ValidateCreditCardValid">*</asp:CustomValidator>

Client side validation:

var Validators = {
CardNumber: function (source, clientside_arguments) {

    var valid_val = true;
    var txtCardNumber = clientside_arguments.Value; //(return the ControlToValidate value)

    //make your checks here

    clientside_arguments.IsValid = valid_val;
}}

server side validation:

protected void ValidateCreditCardValid(object sender, ServerValidateEventArgs e)
    {
       //make your checks here            
       e.IsValid = false;

    }

I solved this problem by creating a variable:

 Boolean fieldIsValid = true;

and in the custom validating expression method I would change the value if arguments weren't true:

if(args.IsValid == false)
            {
                fieldIsValid = false;
            }
            else
            {
                fieldIsValid = true;
            }

Then, I also put that in the submit click method:

protected void submit_Click(object sender, EventArgs e)
        {
            if (fieldIsValid)
            {
                //submit my things
            }
        }