Bootstrap Dropmenu 在点击时自动调整大小

Question

我正在构建一个简单的导航栏，它在最右边有一个 drop-down menu，如下所示：

问题是，当我单击下拉菜单时，导航栏会自动调整大小，如下图所示，这不是我想要的

这是我的 navbar 代码：

<nav class="navbar navbar-dark bg-dark">
  <a class="navbar-brand" href="/dashboard">
    <img
      src="{{ url_for('static', filename='images/logo.png') }}"
      width="30"
      height="30"
      class="d-inline-block align-top"
      alt=""
    />
    App Test
  </a>

  <div>
    <ul class="navbar-nav" style="padding: 0px">
      <li class="nav-item dropdown" style="border: none">
        <a
          class="nav-link dropdown-toggle"
          href="#"
          id="navbarDropdownMenuLink"
          role="button"
          data-toggle="dropdown"
          aria-haspopup="true"
          aria-expanded="false"
        >
          <img
            src="https://s3.eu-central-1.amazonaws.com/bootstrapbaymisc/blog/24_days_bootstrap/fox.jpg"
            width="40"
            height="40"
            class="rounded-circle"
          />
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
          <a class="dropdown-item" href="#">Dashboard</a>
          <a class="dropdown-item" href="#">Edit Profile</a>
          <a class="dropdown-item" href="#">Log Out</a>
        </div>
      </li>
    </ul>
  </div>
</nav>

Answer 1

您忘记添加 navbar-expand 例如 navbar-expand-lg.
正如 document 所说：

Navbars require a wrapping .navbar with .navbar-expand{-sm|-md|-lg|-xl} for responsive collapsing and color scheme classes.

并且：

For navbars that never collapse, add the .navbar-expand class on the navbar. For navbars that always collapse, don’t add any .navbar-expand class.

带有 .dropdown-menu 选择器的 .navbar-expand-xx 包含 position:absolute;，这使得下拉菜单看起来浮动而不是扩展区域。

添加 navbar-expand- class 后，品牌元素上的导航栏需要 flex-grow-1 class 才能将菜单按钮推到右侧。这是 Bootstrap 的 flex utilities。

<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <a class="navbar-brand flex-grow-1" href="/dashboard">
        <img src="{{ url_for('static', filename='images/logo.png') }}" width="30" height="30" class="d-inline-block align-top" alt="">
        App Test
    </a>

    <div>
        <ul class="navbar-nav" style="padding: 0px;">
            <li class="nav-item dropdown" style="border: none;">
                <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                    <img src="https://s3.eu-central-1.amazonaws.com/bootstrapbaymisc/blog/24_days_bootstrap/fox.jpg" width="40" height="40" class="rounded-circle">
                </a>
                <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
                    <a class="dropdown-item" href="#">Dashboard</a>
                    <a class="dropdown-item" href="#">Edit Profile</a>
                    <a class="dropdown-item" href="#">Log Out</a>
                </div>
            </li>
        </ul>
    </div>
</nav>

See it in action.

现在，您可能会看到下拉菜单本身不在屏幕上。您可以修复此使用 menu align option.

<div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbarDropdownMenuLink">
    <a class="dropdown-item" href="#">Dashboard</a>
    <a class="dropdown-item" href="#">Edit Profile</a>
    <a class="dropdown-item" href="#">Log Out</a>
</div>

See it in action.

Bootstrap Dropmenu 在点击时自动调整大小

Bootstrap Dropmenu automatically resizes on click

html

css

navbar

bootstrap-4