有没有办法阻止MVC 5中的表单提交？

Question

I have a from.

@using (Html.BeginForm())
{
 // From content 
 <div class="form-group btn-group">
                <button type="submit" class="btnPrimaryStyle btn  col-sm-3 col-xs-12 pull-left">Save</button>
            </div>
}

Everything is working fine. I have a dropdwon which is out of the form. I want to check, if dropdown value is selected,then form can be submitted otherwise it will not submit. In short, the dropdown selection is required and it is out of the form. I can check the value of dropdwon weather it is selected or not with jquery or javascript. My question is how i prevent to submit the form if value is not selected?

Answer 1

With jQuery it's simple:

$("#your-form-id").submit(function (e) { // note that it's better to use form Id to select form
      if($("#YourDropDownID").val() == 0 || $("#YourDropDownID").val() == '') // here you check your drop down selected value
      {
         e.preventDefault(); // here you stop submitting form
      }
}

To set id to your form use this overload:

Html.BeginForm(null, null, FormMethod.Post, new { id = "your_form_id" })

Answer 2

I think the most correct way to handle this is to use validation http://www.asp.net/mvc/overview/getting-started/introduction/adding-validation

Mark the field of your model that bound with dropdown list with validation attribute. The advantage of this method - you can validate on server side by calling ModelState.IsValid . Server validation will work even if javascript will be disabled.