我目前正在尝试使用引导程序构建一个网站，这是一个非常基本的网站，我正在尝试设置包含图像轮播的主页，并且在设置导航栏时遇到问题。我似乎无法获得包含徽标的浮动居中导航栏。我想将徽标用作主页的href，然后有一个标记为照片的按钮，该按钮将具有照片的下拉菜单和一个在主页上具有锚点部分的联系页面。我以前使用过引导程序，但还没有达到我感觉 100% 舒适的程度。我已经设法利用各种堆栈溢出论坛来解决我的其他问题，但在弄清楚如何做到这一点时遇到了问题。
以下是我的导航栏代码的要点。
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="generator" content="Jekyll v3.8.5">
<title>blah</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js"></script>
<link rel="canonical" href="https://getbootstrap.com/docs/4.3/examples/carousel/">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous"> -->
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
<!-- Bootstrap core CSS -->
<link href="/docs/4.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<style>
.bd-placeholder-img {
font-size: 1.125rem;
text-anchor: middle;
-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
}
@media (min-width: 768px) {
.bd-placeholder-img-lg {
font-size: 3.5rem;
}
}
.headerrow {
text-align: center;
padding-top: 5%;
padding-bottom: 5%;
}
img.caro {
width: 140;
height: 140;
}
</style>
<!-- Custom styles for this template -->
<link href="carousel.css" rel="stylesheet">
</head>
<body>
<header>
<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
<a href="#" class="navbar-left"><img src="logo2.png" style="width:8%; height:8%;"></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" id="navbarCollapse">
<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">
<a class="nav-link disabled" href="#">Disabled</a>
</li>
</ul>
</div>
</nav>
</header>
<main role="main">
<div class="container">
<h2>Carousel Example</h2>
<div id="myCarousel" class="carousel slide" data-ride="carousel">
<!-- Wrapper for slides -->
<div class="carousel-inner" role="listbox" style="border-radius: 15px; width:100%; height: 600px !important;">
<div class="item active">
<img src="cover.jpg" alt="Cover1" style="width:100%;">
</div>
<div class="item">
<img src="cover2.jpg" alt="Cover2" style="width:100%;">
</div>
<div class="item">
<img src="LogChimneyOut.jpg" alt="Cover3" style="width:100%;">
</div>
<div class="item">
<img src="Fireplace3.jpg" alt="Cover3" style="width:100%;">
</div>
<div class="item">
<img src="Deck1.jpg" alt="Cover3" style="width:100%;">
</div>
<div class="item">
<img src="Wall2.jpg" alt="Cover3" style="width:100%;">
</div>
<div class="item">
<img src="Fireplace2.jpg" alt="Cover3" style="width:100%;">
</div>
</div>
<!-- Left and right controls -->
<a class="left carousel-control" href="#myCarousel" data-slide="prev">
<span class="glyphicon glyphicon-chevron-left"></span>
<span class="sr-only">Previous</span>
</a>
<a class="right carousel-control" href="#myCarousel" data-slide="next">
<span class="glyphicon glyphicon-chevron-right"></span>
<span class="sr-only">Next</span>
</a>
</div>
</div>
这包括导航栏以及其下方的轮播图像幻灯片。我正在尝试在轮播的顶部获得一个浮动的中心导航栏，其中包含徽标、图片按钮和联系页面。我在其他地方寻找导航栏，但似乎总是破坏轮播部分。我肯定不是HTML或引导程序最伟大的，但我在这里尝试。谢谢。
在navbar-nav菜单中，创建一个新的列表项并将包含徽标图像的a标记移动到其中，最后将mr-auto类替换为mx-auto、align-items-center类以使所有项居中。
<ul class="navbar-nav mx-auto align-items-center">
<li class="nav-item"><a href="nav-link"><img src=".." alt="..">logo</a></li>
<li class="nav-item"><a class="nav-link" href="#">Link</a></li>
</ul>
请在此处查看弹性框对齐方式在 BS4 中的工作原理
对于下拉菜单按钮，请遵循以下结构：
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="dropdown_id" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Photos</a>
<div class="dropdown-menu" aria-labelledby="dropdown_id">
<a class="dropdown-item" href="#">Photos</a>
</div>
</li>
请注意，在您的代码段中，您不必要地链接了 不同版本的引导程序文件。按照此介绍进行操作 以查看如何在您的网站中正确包含引导程序。
例：
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
<header>
<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
<button class="navbar-toggler ml-auto" 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" id="navbarCollapse">
<ul class="navbar-nav mx-auto align-items-md-center">
<li class="nav-item">
<a class="navbar-brand" href="#"><img src="https://via.placeholder.com/50&text=logo" alt="logo" width="50px" height="50px"></a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="dropdown01" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Photos</a>
<div class="dropdown-menu" aria-labelledby="dropdown01">
<a class="dropdown-item" href="#">Photo</a>
</div>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Contact</a>
</li>
</ul>
</div>
</nav>
</header>
<main role="main">
<div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">
<!-- Indicators -->
<ol class="carousel-indicators">
<li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
<li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
<li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
</ol>
<!-- The slideshow -->
<div class="carousel-inner">
<div class="carousel-item active">
<img src="//source.unsplash.com/random/1100x400" alt="Los Angeles" width="1100" height="400" class="w-100 h-100">
</div>
<div class="carousel-item">
<img src="//source.unsplash.com/random/1100x400" alt="Chicago" width="1100" height="400" class="w-100 h-100">
</div>
<div class="carousel-item">
<img src="//source.unsplash.com/random/1100x400" alt="New York" width="1100" height="400" class="w-100 h-100">
</div>
</div>
<!-- Left and right controls -->
<a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
<span class="carousel-control-prev-icon" aria-hidden="true"></span>
<span class="sr-only">Previous</span>
</a>
<a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
<span class="carousel-control-next-icon" aria-hidden="true"></span>
<span class="sr-only">Next</span>
</a>
</div>
</main>