如何在悬停时更改引导程序 4 导航栏切换器的颜色？

Question

我正在使用 Bootstrap 4，我希望我的导航栏切换图标（称为汉堡菜单）在 :hover 状态下更改颜色。这是我一直在尝试的，但它不起作用：

.navbar-light .navbar-toggler .menu-icon:hover,
.navbar-light .navbar-toggler .menu-icon:active,
.navbar-light .navbar-toggler .menu-icon:focus {
    color: red !important;
}

这是我的代码：

.navbar-light .navbar-toggler .menu-icon:hover,
.navbar-light .navbar-toggler .menu-icon:active,
.navbar-light .navbar-toggler .menu-icon:focus {
  color: red !important;
}

<nav class="navbar navbar-expand-lg navbar-light bg-white">
  <a class="navbar-brand" href="index.html">
    <img src="images/logo-paygol.svg" alt="Logo Paygol">
  </a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarTopMenu" aria-controls="navbarTopMenu" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon menu-icon"></span>
    </button></nav>

Answer 1

嘿，据我所知，bootstrap 4 正在使用图像 URL 添加图标。这意味着它是一个图像，您不能在图像上添加hover。但是有一个迂回的地方。

所以你必须使用自定义图标并为其添加悬停，如下所示，我将在此示例中使用 fontawesome。

.navbar button.navbar-toggler:hover {
  color: red;
}


/* or 

.navbar .navbar-toggler span:hover i {
  color: red;
}

/*



/* 

or

.navbar .navbar-toggler span i:hover {
  color: red;
}
*/

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css" integrity="sha512-1PKOgIY59xJ8Co8+NE6FZ+LOAZKjy+KY8iq0G4B3CyeY6wYHN3yt9PW0XpSriVlkMXe40PTKnXrLnZ9+fkDaog==" crossorigin="anonymous" />

<!-- CSS only -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">



<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> -->
          <span><i class="fas fa-bars"></i></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>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>

<!-- JS, Popper.js, and jQuery -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.1/dist/umd/popper.min.js" integrity="sha384-9/reFTGAW83EW2RDu2S0VKaIzap3H66lZH81PoYlFhbGU+6BZp6G7niu735Sk7lN" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script>

如你所见，我确实替换了 bootstrap 此处使用的图标

<span class="navbar-toggler-icon"></span>

我使用了fontawesome的我的如下

  <span><i class="fas fa-bars"></i></span>

现在悬停效果可以使用，因为它是一种字体，您可以非常轻松地更改颜色和大小。

我希望这能回答你的问题。如果不这样做，请告诉我。我会尽力编辑我的答案以适合您的问题。