我正在将一个网站从bootstrap 3升级到4(测试版).我用来强调活动导航栏链接的CSS不再有效.它不是强调项目的下划线,而是强调页面的整个宽度.如何在bootstrap 4中为活动导航项加下划线？
Bootstrap 3 css
.navbar-default .navbar-nav > .active:after {
position: absolute;
bottom: 0;
left: 0;
width: 100%;
content: " ";
border-bottom: 5px solid #5BC0EB;
}
尝试Bootstrap 4 css
.navbar-light .navbar-nav .active::after {
position: absolute;
bottom: 0;
left: 0;
width: 100%;
content: " ";
border-bottom: 5px solid #5BC0EB;
}
HTML
<nav class="navbar fixed-top navbar-light bg-light navbar-expand-md">
<div class="container">
<a class="navbar-brand" href="#">My Website</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarCollapse" aria-controls="navbarCollapse"
aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse justify-content-end" id="main-nav-collapse">
<ul class="navbar-nav">
<li class="nav-item active"><a class="nav-link" href="#about">About</a></li>
<li class="nav-item"><a class="nav-link" href="#classes">Classes</a></li>
<li class="nav-item"><a class="nav-link" href="#gallery">Gallery</a></li>
<li class="nav-item"><a class="nav-link" href="#events">Events</a></li>
<li class="nav-item"><a class="nav-link" href="#contact">Contact</a></li>
<li class="nav-item"><a class="nav-link" href="#offers">Offers</a></li>
</ul>
</div>
</div>
</nav>
解决方法
这是因为你的定位.
尝试设置你的li的相对位置,然后设置li里面的标签,它将绝对定位如下
.navbar-nav > li {
float: left;
position: relative;
}
.navbar-light .navbar-nav .active a::after {
border-bottom: 5px solid #5bc0eb;
bottom: -10px;
content: " ";
left: 0;
position: absolute;
right: 0;
}
希望能帮助到你.
