Multi-Select listbox - check if user selected Select All option

Question

I have a MultiSelect Listbox

@Html.ListBoxFor(model => model.DealerScopeDealerProvider.DealerScopeProvider, new MultiSelectList(providers, "ProviderCode", "ProviderName"), new { id = "providerfilter" })


$('#providerfilter').multiselect({
    search: true,
    selectAll: true,
});

which renders HTML like this:

<select id="providerfilter" multiple="multiple">
<option></option>
</select>
<div>
<a href="#" class="ms-selectall global chkimg">Select all</a>
<a href="#" class="ms-unselectall global unchkimg">Unselect all</a>
<a href="#" class="crosimg"></a>
</div>

I want to know if user selected Select all option or not. How can I achieve this using jquery?

Answer 1

use below jquery to get weather checkbox is select or not

  if ($('.ms-selectall').is(":checked")) 
  {   
     // selectall button is selected 
  }
  else if($('.ms-unselectall ').is(":checked")) 
  {
     // unselectall  button is selected  
  }