select2 - 總是下拉，而不是dropdrop

Question

如何強制select2總是下拉，永不dropup？

我想這個解決方案，但是它不工作：This doesn't work

$("#e1").select2() 
.on('select2-open', function() { 

// however much room you determine you need to prevent jumping 
     var requireHeight = 600; 
     var viewportBottom = $(window).scrollTop() + $(window).height(); 

     // figure out if we need to make changes 
     if (viewportBottom < requireHeight) 
     {   
      // determine how much padding we should add (via marginBottom) 
      var marginBottom = requireHeight - viewportBottom; 

      // adding padding so we can scroll down 
      $(".aLwrElmntOrCntntWrppr").css("marginBottom", marginBottom + "px"); 

      // animate to just above the select2, now with plenty of room below 
      $('html, body').animate({ 
       scrollTop: $("#e1").offset().top - 10 
      }, 1000); 
     } 
    }); 

jsFiddle

Answer 1

這爲我工作：

$.fn.select2.amd.require([ 
    'select2/selection/multiple', 
    'select2/selection/search', 
    'select2/dropdown', 
    'select2/dropdown/attachContainer', 
    'select2/dropdown/closeOnSelect', 
    'select2/utils' 
], function (MultipleSelection, Search, Dropdown, AttachContainer, CloseOnSelect, Utils) { 
    var SelectionAdapter = Utils.Decorate(
    MultipleSelection, 
    Search 
); 

    var DropdownAdapter = Utils.Decorate(
    Utils.Decorate(
     Dropdown, 
     CloseOnSelect 
    ), 
    AttachContainer 
); 

    $('#e1').select2({ 
    dropdownAdapter: DropdownAdapter 
    }); 
}); 

jsFiddle