自举4导航栏与搜索输入/图标放置（绝对位置）不工作时更改最大高度和溢流-Y

Question

我试图做一个搜索输入与引导4导航栏中嵌入搜索图标的工作是显示在移动菜单时。下面是很容易的工作我的自举3版...

我有一个很长的“移动”菜单，由于应用程序的性质，所以我想在最大高度和溢出-Y应用到导航栏倒塌，因此不会覆盖整个屏幕。

然而，当我在引导4适用的风格，我的搜索图标不留“内部”，输入：

我已经应用到我的搜索输入的风格是：

<div class="has-search">
    <span class="fa fa-search form-control-feedback execute-quick-search"></span>
    <input type="text" class="form-control quick-search" placeholder="Quick Search">
</div>

.has-search .form-control {
  padding-right: 2.375rem;
}

.has-search .form-control-feedback {
  position: absolute;
  z-index: 2;
  display: block;
  width: 2.375rem;
  height: 2.375rem;
  line-height: 2.375rem;
  text-align: center;
  pointer-events: auto;
  cursor: pointer;
  right: 1.1875rem;
}

我能够做的搜索图标停留里面输入，如果我申请最大高度/溢流-Y样式整个.navbar元素。但是，这不是我要的，更糟的是外观，它允许移动togglerButton被滚动到屏幕。我已再现错误小提琴。

Fiddle

Answer 1

添加position: relative到has-search。也适用max-height等，以navbar-collapse仅在移动视图。

请参见下面的演示：

.has-search { /* ADDED */
  position: relative;
}

.has-search .form-control {
  padding-right: 2.375rem;
}

.has-search .form-control-feedback {
  position: absolute;
  z-index: 2;
  display: block;
  width: 2.375rem;
  height: 2.375rem;
  line-height: 2.375rem;
  text-align: center;
  pointer-events: auto;
  cursor: pointer;
  right: 1.1875rem;
}
@media (max-width: 991px) { /* ADDED */
  .navbar-collapse {
    max-height: 150px;
    overflow-y: auto;
  }
}

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/css/bootstrap.min.css" />
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.1/css/all.css" />
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.6/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/js/bootstrap.min.js"></script>

<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <a class="navbar-brand" href="#">Navbar</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>

  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item active">
        <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Link</a>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
              Dropdown
            </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
          <a class="dropdown-item" href="#">Action</a>
          <a class="dropdown-item" href="#">Another action</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="#">Something else here</a>
        </div>
      </li>
      <li class="nav-item">
        <a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
      </li>
    </ul>
    <div class="has-search">
      <span class="fa fa-search form-control-feedback execute-quick-search"></span>
      <input type="text" class="form-control quick-search" placeholder="Quick Search">
    </div>
  </div>
</nav>
<h1>Hello, world!</h1>