css - Bootstrap 导航栏无法正常工作

Question

我的 bootstrap 导航栏有问题，当它全屏显示时，顶部会出现一个小图标栏，而当调整窗口大小时，相同的图标栏会保留在那里并且按钮不会出现，首先是代码:

<header>
    <nav role="navigation" class="navbar navbar-inverse" style="border-radius:0px;">
        <!-- Brand and toggle get grouped for better mobile display -->
        <div class="navbar-header">
            <button type="button" data-target="#navbarCollapse" data-toggle="collapse" class="navbar-toggle">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <a href="index.php" class="navbar-brand">Brand</a>
        </div>
        <!-- Collection of nav links, forms, and other content for toggling -->
        <div id="navbarCollapse" class="collapse navbar-collapse">
            <ul class="nav navbar-nav">
                <li class="active"><a href="index.php">Home</a></li>
                <li><a href="index.php?p=la">Movies List</a></li>
                <li><a href="index.php?p=gl">Genre List</a></li>

            </ul>
            <form role="search" class="navbar-form navbar-left">
                <div class="form-group">
                    <input type="text" placeholder="Search" class="form-control">
                </div>
            </form>
            <ul class="nav navbar-nav navbar-right">
                <li><a href="admin/index.php?p=log">Login</a></li>
            </ul>
        </div>
    </nav>
</header>

下面是它的截图:

Answer 1

看起来您可能缺少 javascript 组件包括:

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>