图标列表：https://www.runoob.com/try/demo_source/bootstrap3-glyph-icons.htm
glyphicon gyphicon-sort-by-attributes
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Bootstrap 实例 - 如何使用字形图标（Glyphicons）</title>
<link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<p>
<button type="button" class="btn btn-default">
<span class="glyphicon glyphicon-sort-by-attributes"></span>
</button>
<button type="button" class="btn btn-default">
<span class="glyphicon glyphicon-sort-by-attributes-alt"></span>
</button>
<button type="button" class="btn btn-default">
<span class="glyphicon glyphicon-sort-by-order"></span>
</button>
<button type="button" class="btn btn-default">
<span class="glyphicon glyphicon-sort-by-order-alt"></span>
</button>
</p>
<button type="button" class="btn btn-default btn-lg">
<span class="glyphicon glyphicon-user"></span> User
</button>
<button type="button" class="btn btn-default btn-sm">
<span class="glyphicon glyphicon-user"></span> User
</button>
<button type="button" class="btn btn-default btn-xs">
<span class="glyphicon glyphicon-user"></span> User
</button>
</body>
</html>
menu 字体图标
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>导航栏的字形图标</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">
<style>
body {
padding-top: 50px;
padding-left: 50px;
}
</style>
</head>
<body>
<div class="navbar navbar-fixed-top navbar-inverse" role="navigation">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
<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="#">Project name</a>
</div>
<div class="collapse navbar-collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#"><span class="glyphicon glyphicon-home"></span> Home</a></li>
<li><a href="#shop"><span class="glyphicon glyphicon-shopping-cart"></span> Shop</a></li>
<li><a href="#support"><span class="glyphicon glyphicon-headphones"></span> Support</a></li>
</ul>
</div>
</div>
</div>
<script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
</body>
</html>
<button type="button" class="btn btn-primary btn-lg">
<span class="glyphicon glyphicon-user"></span> User
</button>
<button type="button" class="btn btn-primary btn-lg" style="text-shadow: black 5px 3px 3px;">
<span class="glyphicon glyphicon-user"></span> User
</button>
字体图标参考：https://www.runoob.com/bootstrap/bootstrap-glyphicons.html
