active加在progress-bar也可以实现动态
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>进度条--动态条纹进度条</title>
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
</head>
<body>
<h2>代码任务部分</h2>
<div class="progress progress-striped ">
<div class="progress-bar active" style="width:50%"></div>
</div>
<script src="http://libs.baidu.com/jquery/1.9.0/jquery.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
</body>
</html>
