Bootstrap 的导航栏下拉菜单无法在自定义断点下方正确打开

Question

我应用了以下代码来为这个问题中讨论的 bootstraps 导航栏实现自定义断点：Bootstrap custom breakpoint

@media (max-width: 1000px) {
  .navbar-header {
      float: none;
  }
  .navbar-left,.navbar-right {
      float: none !important;
  }
  .navbar-toggle {
      display: block;
  }
  .navbar-collapse {
      border-top: 1px solid transparent;
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.1);
  }
  .navbar-fixed-top {
      top: 0;
      border-width: 0 0 1px;
  }
  .navbar-collapse.collapse {
      display: none!important;
  }
  .navbar-nav {
      float: none!important;
      margin-top: 7.5px;
  }
  .navbar-nav>li {
      float: none;
  }
  .navbar-nav>li>a {
      padding-top: 10px;
      padding-bottom: 10px;
  }
  .collapse.in{
      display:block !important;
  }
}

导航栏折叠到自定义断点下方 @media (max-width: 1165px) 但是下拉菜单无法正确打开。

不过，对于 bootstrap 的默认断点 (768px)，它可以正常工作。

anybuddy 可以告诉我为什么它不适用于自定义断点吗？是 bootstrap jquery/javascript 问题吗？如何让它为自定义断点正确下拉。

谢谢 dk

Answer 1

bootstrap.css 文件包含以下代码：

@media (max-width: 767px) {
  .navbar-nav .open .dropdown-menu {
    position: static;
    float: none;
    width: auto;
    margin-top: 0;
    background-color: transparent;
    border: 0;
    -webkit-box-shadow: none;
            box-shadow: none;
  }
  .navbar-nav .open .dropdown-menu > li > a,
  .navbar-nav .open .dropdown-menu .dropdown-header {
    padding: 5px 15px 5px 25px;
  }
  .navbar-nav .open .dropdown-menu > li > a {
    line-height: 20px;
  }
  .navbar-nav .open .dropdown-menu > li > a:hover,
  .navbar-nav .open .dropdown-menu > li > a:focus {
    background-image: none;
  }
}

因此您可以将此代码用于媒体查询 @media (max-width: 1000px)（或 @media (max-width: 1065px)，如果需要）。

我已将此 CSS 应用到 Default navbar. Please check the result: https://jsfiddle.net/glebkema/zd9axad0/

@import url('https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css');

@media (max-width: 1000px) {
  /* dropdown */
  .navbar-nav .open .dropdown-menu {
    position: static;
    float: none;
    width: auto;
    margin-top: 0;
    background-color: transparent;
    border: 0;
    -webkit-box-shadow: none;
            box-shadow: none;
  }
  .navbar-nav .open .dropdown-menu > li > a,
  .navbar-nav .open .dropdown-menu .dropdown-header {
    padding: 5px 15px 5px 25px;
  }
  .navbar-nav .open .dropdown-menu > li > a {
    line-height: 20px;
  }
  .navbar-nav .open .dropdown-menu > li > a:hover,
  .navbar-nav .open .dropdown-menu > li > a:focus {
    background-image: none;
  }
  
  /* collapse */
  .navbar-header {
      float: none;
  }
  .navbar-left,.navbar-right {
      float: none !important;
  }
  .navbar-toggle {
      display: block;
  }
  .navbar-collapse {
      border-top: 1px solid transparent;
      box-shadow: inset 0 1px 0 rgba(255,255,255,0.1);
  }
  .navbar-fixed-top {
      top: 0;
      border-width: 0 0 1px;
  }
  .navbar-collapse.collapse {
      display: none!important;
  }
  .navbar-nav {
      float: none!important;
      margin-top: 7.5px;
  }
  .navbar-nav>li {
      float: none;
  }
  .navbar-nav>li>a {
      padding-top: 10px;
      padding-bottom: 10px;
  }
  .collapse.in{
      display:block !important;
  }  
}

<nav class="navbar navbar-default">
  <div class="container">
    <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">Brand</a>
    </div>

    <!-- Collect the nav links, forms, and other content for toggling -->
    <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
      <ul class="nav navbar-nav">
        <li class="active"><a href="#">Link <span class="sr-only">(current)</span></a></li>
        <li><a href="#">Link</a></li>
        <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
          <ul class="dropdown-menu">
            <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>
            <li role="separator" class="divider"></li>
            <li><a href="#">One more separated link</a></li>
          </ul>
        </li>
      </ul>
      <ul class="nav navbar-nav navbar-right">
        <li><a href="#">Link</a></li>
        <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
          <ul class="dropdown-menu">
            <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>
        </li>
      </ul>
    </div><!-- /.navbar-collapse -->
  </div><!-- /.container-fluid -->
</nav>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>

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