从optgroup中选择单个项目

Question

我想从选择中选择4个项目，从optgroup中选择单个项目。我尝试了通过silviomoreto bootstrap-silviomoreto进行引导选择，但它不能像预期的那样工作……我只想使用jquery来完成这项工作，不一定在插件之上。

​

<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

您可以像这样尝试：

$("option").on("click", function(){
    if($(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