Question

我知道很难为我的问题提供代码，但是我想知道如何使Bootstrap下拉菜单在默认情况下打开后无法关闭（保持打开状态）？

谢谢

Answer 1

您必须使用2个功能，其中一个onclick dropdown和一个onclick body 使用e.stopPropagation();来防止关闭...

var flag=true;
$( ".dropdown-toggle" ).click(function(e) {
  if (!flag)
     e.stopPropagation();
  else
     flag=false;
});
$(document).on('click', ':not(.dropdown)', function(e) {
  if ($(this).closest('.dropdown').length == 0) {
      e.stopPropagation();
  }
});

 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
  
<div class="container">
                                        
  <div class="dropdown">
    <button class="btn btn-primary dropdown-toggle" type="button" data-toggle="dropdown">Dropdown Example
    <span class="caret"></span></button>
    <ul class="dropdown-menu">
      <li><a href="#">HTML</a></li>
      <li><a href="#">CSS</a></li>
      <li><a href="#">JavaScript</a></li>
    </ul>
  </div>
</div>

Answer 2

此解决方案在Bootstrap隐藏（hide.bs.dropdown）事件上停止传播，从而阻止其继续进行到隐藏（hidden.bs.dropdown）事件。您可以在这里阅读更多内容：http://css-tricks.com/dangers-stopping-event-propagation/

我个人更喜欢这种方式，因为它使用内置的Bootstrap下拉事件，可以在以下位置找到该事件：http://getbootstrap.com/javascript/#dropdowns-events

$(function () {
  $('.dropdown.keep-open').on({
    "shown.bs.dropdown": function () {
      $(this).data('closable', false);
    },
    "click": function (event) {
      $(this).data('closable', false);
    },
    "hide.bs.dropdown": function (event) {
      temp = $(this).data('closable');
      $(this).data('closable', true);
      return temp;
    }
  });
});

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css">

<h3>Default behaviour</h3>
<div class="dropdown">
  <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="true">
    Dropdown
    <span class="caret"></span>
  </button>
  <ul class="dropdown-menu" aria-labelledby="dropdownMenu1">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
    <li role="separator" class="divider"></li>
    <li><a href="#">Separated link</a></li>
  </ul>
</div>
<hr/>
<h3>Preventing bootstrap dropdown from closing on click</h3>
<div class="dropdown keep-open">
  <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="true">
    Dropdown
    <span class="caret"></span>
  </button>
  <ul class="dropdown-menu" aria-labelledby="dropdownMenu1">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
    <li role="separator" class="divider"></li>
    <li><a href="#">Separated link</a></li>
  </ul>
</div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>

如何使Bootstrap下拉菜单最初处于打开状态，此后无法关闭

2 个答案: