bootstrap 的学习非常简单，并且它所提供的样式又非常精美。只要稍微简单的学习就可以制作出漂亮的页面。
bootstrap提供了三种类型的下载：
1、用于生产环境的 Bootstrap
编译并压缩后的 CSS、JavaScript 和字体文件。不包含文档和源码文件。
2、Bootstrap 源码
Less、JavaScript 和 字体文件的源码，并且带有文档。需要 Less 编译器和一些设置工作。
3、Sass
这是 Bootstrap 从 Less 到 Sass 的源码移植项目，用于快速地在 Rails、Compass 或 只针对 Sass 的项目中引入。
其实我们不用下载bootstrap也可以使用它：
Bootstrap 中文网 为 Bootstrap 专门构建了自己的免费 CDN 加速服务。基于国内云厂商的 CDN 服务，访问速度更快、加速效果更明显、没有速度和带宽限制、永久免费。
base.html
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ --> <title>Bootstrap 101 Template</title> <!-- Bootstrap --> <link rel="stylesheet" href="http://cdn.bootcss.com/bootstrap/3.3.4/css/bootstrap.min.css" rel="external nofollow" > </head> <body> <h1>你好，bootstrap！</h1> <!-- jQuery (necessary for Bootstrap's JavaScript plugins) --> <script src="http://cdn.bootcss.com/jquery/1.11.2/jquery.min.js"></script> <!-- Include all compiled plugins (below), or include individual files as needed --> <script src="http://cdn.bootcss.com/bootstrap/3.3.4/js/bootstrap.min.js"></script> </body> </html>
base.html中已经引入了bootstrap，将其保存，我们就可以使用bootstrap提供的样式了。
字体图标
bootstrap默认提供了二百多个图标。我们可以通过span标签来使用这些图标：
<h3>图标</h3> <span class="glyphicon glyphicon-home"></span> <span class="glyphicon glyphicon-signal"></span> <span class="glyphicon glyphicon-cog"></span> <span class="glyphicon glyphicon-apple"></span> <span class="glyphicon glyphicon-trash"></span> <span class="glyphicon glyphicon-play-circle"></span> <span class="glyphicon glyphicon-headphones"></span>
按钮
<button></button>标签用于创建按钮，bootstrap提供了丰富的按钮样式。 <h3>按钮</h3> <button type="button" class="btn btn-default">按钮</button> <button type="button" class="btn btn-primary">primary</button> <button type="button" class="btn btn-success">success</button> <button type="button" class="btn btn-info">info</button> <button type="button" class="btn btn-warning">warning</button> <button type="button" class="btn btn-danger">danger</button> <h3>按钮尺寸</h3> <button type="button" class="btn btn-default">按钮</button> <button type="button" class="btn btn-primary btn-lg">primary</button> <button type="button" class="btn btn-success btn-sm">success</button> <button type="button" class="btn btn-info btn-xs">info</button> <h3>把图标显示在按钮里</h3> <button type="button" class="btn btn-default"><span class="glyphicon glyphicon-home"></span> 按钮</button>
按钮除了有默认的大小外，bootstrap还提供三个参数来调整按钮的大小，分别是：btn-lg、btn-sm和btn-xs。
下拉菜单
下拉菜单是最常见的交互之一，bootstrap提供了漂亮的样式。
<h3>下拉菜单</h3> <div class="dropdown"> <button class="btn btn-primary dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown" aria-expanded="true"> Dropdown <span class="caret"></span> </button> <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1"> <li role="presentation"><a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Action</a></li> <li role="presentation"><a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Another action</a></li> <li role="presentation"><a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Something else here</a></li> <li role="presentation"><a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Separated link</a></li> </ul> </div>
输入框
通过<input></input>标签去创建输入框。
<h3>输入框</h3> <div class="input-group"> <span class="glyphicon glyphicon-user"></span> <input type="text" placeholder="username"> </div> <div class="input-group"> <span class="glyphicon glyphicon-lock"></span> <input type="password" placeholder="password"> </div>
导航栏
导航栏作为整个网站的指引必不可少。
<h3>导航栏</h3>
<nav class="navbar navbar-inverse navbar-fixed-top">
<div id="navbar" class="navbar-collapse collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Home</a></li>
<li><a href="#about" rel="external nofollow" >About</a></li>
<li><a href="#contact" rel="external nofollow" >Contact</a></li>
<li class="dropdown">
<a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">Dropdown <span class="caret"></span></a>
<ul class="dropdown-menu" role="menu">
<li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Action</a></li>
<li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Another action</a></li>
<li class="divider"></li>
<li class="dropdown-header">Nav header</li>
<li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Separated link</a></li>
</ul>
</li>
</ul>
</div><!--/.nav-collapse -->
</div>
</nav>
表单
人与系统之间数据的传递都需要依靠表单来完成。比如注册/登录信息的提交，查询条件的提交等。用<form></form>标签来创建表单。
<h3>表单</h3> <form> <div class="form-group"> <span class="glyphicon glyphicon-user"></span> <input type="email" id="exampleInputEmail1" placeholder="Enter email"> </div> <div class="form-group"> <span class="glyphicon glyphicon-lock"></span> <input type="password" id="exampleInputPassword1" placeholder="Password"> </div> <div class="form-group"> <label for="exampleInputFile">File input</label> <input type="file" id="exampleInputFile"> <p class="help-block">Example block-level help text here.</p> </div> <div class="checkbox"> <label> <input type="checkbox"> Check me out </label> </div> <button type="submit" class="btn btn-default">Submit</button> </form>
警告框
警告框是系统向用户传达信息和提供指引的重要手段。没有针对警告框的标签，通过bootstrap所提供的样式可以瞬间制作出漂亮的警告框。
<h3>警告框</h3> <div class="alert alert-warning alert-dismissible" role="alert"> <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">×</span></button> <strong>Warning!</strong> Better check yourself, you're not looking too good. </div> <div class="alert alert-success" role="alert"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="alert-link">success!</a> </div> <div class="alert alert-info" role="alert"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="alert-link">info!</a> </div> <div class="alert alert-warning" role="alert"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="alert-link">warning!</a> </div> <div class="alert alert-danger" role="alert"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="alert-link">danger!</a> </div>
进度条
系统的处理过程往往需要用户等待，进度条可以让用户感知到系统的处理过程，从而增加容忍度。
<h3>进度条</h3> <div class="progress"> <div class="progress-bar" role="progressbar" aria-valuenow="70" aria-valuemin="0" aria-valuemax="100" style="width: 60%;"> 70% </div> </div>
