Bootstrap 4嵌套下拉列表?

本文介绍了Bootstrap 4嵌套下拉列表?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我想做的是，如果有人单击艺术，则应该显示历史社会学和地理"子菜单.现在，当有人点击艺术"时，它应该会出现.
https://jsfiddle.net/0e7jdfza/

What I am trying to do is if anyone click on arts then History sociology and geography submenu should show up. It should now appear when someone clicks on Arts.
https://jsfiddle.net/0e7jdfza/

我尝试添加此代码 https://jsfiddle.net/w3zyLmgb/代替art li和ul，但它在下拉菜单中起作用，尽管它在此下拉菜单之外起作用

I tried adding this code https://jsfiddle.net/w3zyLmgb/ in place of arts li and ul but it down work inside the dropdown though it works outside this dropdown menu

<!doctype html>
            <html lang="en">
              <head>
                <!-- Required meta tags -->
                <meta charset="utf-8">
                <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

                <!-- Bootstrap CSS -->
                <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

                <title>Hello, world!</title>
              </head>
              <body>
    <div class="dropdown show">
                  <a class="btn btn-secondary dropdown-toggle" href="#" role="button" id="dropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    Select Streams
                  </a>
                  <ul class="dropdown-menu" aria-labelledby="dropdownMenuLink">
                    <li><a class="dropdown-item" href="#">Science</a></li>
                    <li><a class="dropdown-item" href="#">Commerce</a></li>
                    <li class="nav-item dropdown"><a class="dropdown-item" href="#">Arts</a>
                      <ul>
                        <li>History</li>
                        <li>Sociology</li>
                        <li>Geogrphy</li>
                      </ul>
                    </li>
                </ul>
                 </div>


            <!-- Optional JavaScript -->
            <!-- jQuery first, then Popper.js, then Bootstrap JS -->
            <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
            <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
            <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
          </body>
        </html>

推荐答案

我认为这是您要找的东西.

I think this is kinda what you are looking for.

您的更新后的代码具有其中给出的建议之一，看起来像给出的示例.

Your updated code with one of the suggestions given in there would look something like the example given.

(如果您使用Angular，则可以使用 ngx-dropdowns ，它们有一个嵌套下拉菜单的解决方案)

(If you use Angular you could use ngx-dropdowns they have a solution for nested dropdowns)

$('.dropdown-menu a.dropdown-toggle').on('click', function(e) {
  if (!$(this).next().hasClass('show')) {
    $(this).parents('.dropdown-menu').first().find('.show').removeClass("show");
  }
  var $subMenu = $(this).next(".dropdown-menu");
  $subMenu.toggleClass('show');


  $(this).parents('li.nav-item.dropdown.show').on('hidden.bs.dropdown', function(e) {
    $('.dropdown-submenu .show').removeClass("show");
  });


  return false;
});

.dropdown-submenu {
  position: relative;
}

.dropdown-submenu a::after {
  transform: rotate(-90deg);
  position: absolute;
  right: 6px;
  top: .8em;
}

.dropdown-submenu .dropdown-menu {
  top: 0;
  left: 100%;
  margin-left: .1rem;
  margin-right: .1rem;
}

<!doctype html>
<html lang="en">

<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

  <!-- Bootstrap CSS -->
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

  <title>Hello, world!</title>
</head>

<body>
  <div class="dropdown show">
    <a class="btn btn-secondary dropdown-toggle" href="#" role="button" id="dropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    Select Streams
                  </a>
    <ul class="dropdown-menu" aria-labelledby="dropdownMenuLink">
      <li><a class="dropdown-item" href="#">Science</a></li>
      <li><a class="dropdown-item" href="#">Commerce</a></li>
      <li class="dropdown-submenu"><a class="dropdown-item dropdown-toggle" href="#">Arts</a>
        <ul class="dropdown-menu">
          <li><a class="dropdown-item" href="#">History</a></li>
          <li><a class="dropdown-item" href="#">Geography</a></li>
          <li><a class="dropdown-item" href="#">Sociology</a></li>

        </ul>
      </li>
    </ul>
  </div>


  <!-- Optional JavaScript -->
  <!-- jQuery first, then Popper.js, then Bootstrap JS -->
  <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>

</html>

这篇关于Bootstrap 4嵌套下拉列表?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！