html - 手机上的导航菜单很古怪？

Question

我正在尝试简化我客户网站背后的代码，因为有一些无关的代码。执行此操作时，导航菜单( Bootstrap )不再有效？它似乎不在屏幕上，我不确定为什么或如何修复它。

<div id="container-para" class="container-fluid">
  <nav class="navbar navbar-default navbar-toggleable-md navbar-expand-lg navbar-inverse bg-inverse justify-content-around fixed-top" >
        <a class="navbar-brand" href="/">    
        <img src="/inc/img/IMG_1877.jpg" alt="Cheapest Used Tires" style="padding-right:1px;border-radius: 6%;"><span>Cheapest Used Tires</span></a>
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavAltMarkup"
                aria-controls="navbarNavAltMarkup" aria-expanded="false" aria-label="Toggle navigation">
            <img class="logo3" src="/inc/img/3logo.jpg">
        </button>

        <div class="collapse navbar-collapse" id="navbarNavAltMarkup">

            <ul class="navbar-nav navbar-justify text-center">

    <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="dealersDropdown" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        <img class="logo3" src="/inc/img/3logo.jpg">
Tire Dealers</a>
        <div class="dropdown-menu" aria-labelledby="dealersDropdown">
            <a class="dropdown-item" href="/tire-dealers.php">Tire Dealers</a>
                        <a class="dropdown-item" href="/construction.php">Tire Services</a>
                        <a class="dropdown-item" href="/construction.php">All Auto Services</a>
            </div>  
        </li>

    <li class="nav-item">
        <a class="nav-link" href="/construction.php">Why Used?</a>
    </li>

    <li class="nav-item">
        <a class="nav-link" href="/construction.php">Tire Science</a>
    </li>

    <li class="nav-item">
        <a class="nav-link" href="/construction.php">Tire Products</a>
    </li>
    <li class="nav-item">
        <a class="nav-link" href="/NewPages/contact.php">Contact Us</a>
    </li>
    <li class="nav-item">
        <form method="post" action="/auth/user/users.php">
            <button class="nav-item nav-link buttons">Login or Join</button>
        </form>
    </li>
</ul>
</div>
</nav>

https://jsfiddle.net/j3rfkrgc/2/

Answer 1

的确，Bootstrap 3 代码不能与 Bootstrap 4 css 一起工作。 Bootstrap 4 几乎是对 Bootstrap 3 的完全重写。因此，几乎所有内容都发生了变化。

这是工作中的 Bootstrap 4 导航栏的样子:

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></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="#">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>

注意:没有navbar-default 和navbar-toggleable-* 类开始。此外，保持 HTML 有效是个好主意。 (有些不是)

Bootstrap 4 导航栏引用:

https://getbootstrap.com/docs/4.0/components/navbar/