Using jQuery Validate's invalidHandler event

问题

I need to add a class to div that is wrapped around the select element upon validation.

$("#Form").validate({
    invalidHandler: function (form, validator) {
        $("[id$='_DropDownList']").each(function () {
            // How do I figure out if $(this) is valid or invalid?
            // Add the class below if invalid.
            $(this).parent().addClass("error");
        });
    }
});

回答1:

You can use the .valid() method, like this:

$("#Form").validate({
    invalidHandler: function (form, validator) {
        $("[id$='_DropDownList']").each(function () {
            if(!$(this).valid())
              $(this).parent().addClass("error");
        });
    }
});

However, the highlight and unhightlight options are specifically for this:

$("#Form").validate({
  highlight: function(element, errorClass, validClass) {
    $(element).parent().removeClass(validClass).addClass(errorClass);
  },
  unhighlight: function(element, errorClass, validClass) {
    $(element).parent().removeClass(errorClass).addClass(validClass);
  }
});

回答2:

It looks like this code is correct:

$(this).parent().addClass("error");

Maybe your issue is with the code surrounding it... Try moving your addClass line outside the function it is in to see if it work there.

回答3:

invalidHandler is only called when the form is submitted and not valid. I believe adding your code under that function alone is enough.

来源：https://stackoverflow.com/questions/4616947/using-jquery-validates-invalidhandler-event