Question

我的网站上有一个菜单，当用户展开菜单时，我试图将其覆盖在屏幕的其余部分上。我已经足够新，可以进行引导了，所以不确定在菜单展开时我应该怎么做。

我的菜单是这样的：

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>

<nav class="navbar navbar-expand-lg">
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    Menu
  </button>
  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav ml-auto">
      <li class="nav-item text-center dropdown">
        <a class="nav-link nav dropdown-toggle products-dropdown" href="#" data-toggle="dropdown" aria-expanded="false">Products</a>
        <ul class="dropdown-menu">
          <li class="dropdown-item d-block">item</li>
          <li class="dropdown-item d-block">item</li>
          <li class="dropdown-item d-block">item</li>
          <li class="dropdown-item d-block">item</li>
        </ul>
      </li>
      <li class="nav-item text-center"><a class="nav-link nav" href="#">Blog</a></li>
      <li class="nav-item text-center"><a class="nav-link nav" href="#">About Us</a></li>
      <li class="nav-item text-center"><a class="nav-link nav" href="#">Contact Us</a></li>
    </ul>
  </div>
</nav>

我尝试给下拉列表提供一个ID，然后在JS if($("#this_id").hasClass("show")){}中给一个类似的函数，但是很显然，这是行不通的，因为只有在页面加载时才显示它。

Answer 1

尝试一下：

$("#navbarSupportedContent").on('show.bs.collapse hide.bs.collapse', function(e) {
  console.log(e.type + " collapse");
});
$("li.dropdown").on('show.bs.dropdown hide.bs.dropdown', function(e) {
  console.log(e.type + " dropdown");
});

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>

<nav class="navbar navbar-expand-lg">
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    Menu
  </button>
  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav ml-auto">
      <li class="nav-item text-center dropdown">
        <a class="nav-link nav dropdown-toggle products-dropdown" href="#" data-toggle="dropdown" aria-expanded="false">Products</a>
        <ul class="dropdown-menu">
          <li class="dropdown-item d-block">item</li>
          <li class="dropdown-item d-block">item</li>
          <li class="dropdown-item d-block">item</li>
          <li class="dropdown-item d-block">item</li>
        </ul>
      </li>
      <li class="nav-item text-center"><a class="nav-link nav" href="#">Blog</a></li>
      <li class="nav-item text-center"><a class="nav-link nav" href="#">About Us</a></li>
      <li class="nav-item text-center"><a class="nav-link nav" href="#">Contact Us</a></li>
    </ul>
  </div>
</nav>

JS-将侦听器添加到引导下拉菜单

1 个答案: