jquery - 从 optgroup 中选择单个项目

Question

我想从 select 中选择 4 个项目，并从 optgroup 中选择单个项目..我尝试了 silviomoreto bootstrap-silviomoreto 的 bootstrap select但它没有按预期工作...我只是想使用 jquery 来做到这一点，不一定是上面的插件..

<select class="selectpicker" multiple data-max-options="4">
    <optgroup label="Group1" data-max-options="1">
      <option>Subject-1</option>
      <option>Subject-2</option>
      <option>Subject-3</option>
    </optgroup>
    <optgroup label="Group2" data-max-options="1">
      <option>Subject-1</option>
      <option>Subject-2</option>
      <option>Subject-3</option>
    </optgroup>
	<optgroup label="Group3" data-max-options="1">
      <option>Subject-1</option>
      <option>Subject-2</option>
     </optgroup>
	<optgroup label="Group5" data-max-options="1">
      <option>Subject-1</option>
      <option>Subject-2</option>
     </optgroup>
	<optgroup label="Group6" data-max-options="1">
     <option>Subject-1</option>
      <option>Subject-2</option>
     </optgroup>
  </select>
</div>

Answer 1

你可以这样尝试:

$("option").on("click", function(){
    if($(this).siblings("option:selected").length) {
       $(this).siblings("option").attr("selected",false);
    }
    if($(this).closest("select").find("option:selected").length>4) {
       $(this).attr("selected",false);    
    }
});

FIDDLE