導覽列以 HTML5 的 nav 元素為主角,通常放在網頁的最上方,如下面的 HTML5 結構圖所示
首先,先做一個常見的Nav Bar樣式
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Navbars</title>
<link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
</head>
<body>
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<a href="#" class="navbar-brand">Koffee</a>
</div>
<div class="collapse navbar-collapse" id="bs-nav-demo">
<ul class="nav navbar-nav">
<li><a href="#">About</a></li>
<li><a href="#">Contact</a></li>
</ul>
<ul class="nav navbar-nav navbar-right">
<li><a href="#">Sign Up</a></li>
<li><a href="#">Login</a></li>
</ul>
</div>
</div>
</nav>
<script src="https://code.jquery.com/jquery-2.1.4.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
</body>
</html>
在一般大小的螢幕看起來沒什麼問題,左邊的兩層式結構
以及右邊的登入及註冊,都可以正常顯示
但只要把螢幕變窄,就會發現選單被遮到了
為了解決這個問題,Bootstrap提供了漢堡選單的做法
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-nav-demo" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
加入上述語法,當螢幕變窄後,就會出現漢堡選單
接著,嘗試在 Nav Bar 加入下拉選單
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li role="separator" class="divider"></li>
<li><a href="#">Separated link</a></li>
<li role="separator" class="divider"></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
</button>
也可以試著在 Nav Bar 加入表單(Form)
<form class="navbar-form navbar-left" role="search">
<div class="form-group">
<input type="text" class="form-control" placeholder="Search">
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
最後,可以試試看把上面學的組合起來
做到有階層式的Nav Bar,並且可以適應螢幕大小
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Navbars</title>
<link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
</head>
<body>
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-nav-demo" aria-expanded="false">
<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="#" class="navbar-brand">Koffee</a>
</div>
<div class="collapse navbar-collapse" id="bs-nav-demo">
<ul class="nav navbar-nav">
<li><a href="#">About</a></li>
<li><a href="#">Contact</a></li>
</ul>
<ul class="nav navbar-nav navbar-right">
<li><a href="#">Sign Up</a></li>
<li><a href="#">Login</a></li>
</ul>
</div>
</div>
</nav>
<!-- DEFAULT NAVBAR -->
<nav class="navbar navbar-default">
<div class="container-fluid">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Brand</a>
</div>
<!-- Collect the nav links, forms, and other content for toggling -->
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Link <span class="sr-only">(current)</span></a></li>
<li><a href="#">Link</a></li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li role="separator" class="divider"></li>
<li><a href="#">Separated link</a></li>
<li role="separator" class="divider"></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
</ul>
<form class="navbar-form navbar-left" role="search">
<div class="form-group">
<input type="text" class="form-control" placeholder="Search">
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
<ul class="nav navbar-nav navbar-right">
<li><a href="#">Link</a></li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li role="separator" class="divider"></li>
<li><a href="#">Separated link</a></li>
</ul>
</li>
</ul>
</div><!-- /.navbar-collapse -->
</div><!-- /.container-fluid -->
</nav>
<script src="https://code.jquery.com/jquery-2.1.4.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
</body>
</html>