----对于用户来说，界面就是程序本身。那么一个漂亮的web一定是你继续使用这个应用的前题。
这一节我们来一起写个Bootstrap的hello wrold。
Bootstrap
Bootstrap 是最受欢迎的 HTML、CSS 和 JS 框架，用于开发响应式布局、移动设备优先的 WEB 项目。
如何使用Bootstrap？
Bootstrap的使用一般有两种方法。一种是引用在线的Bootstrap的样式，一种是将Bootstrap下载到本地进行引用。
引用在线样式：
引用在线样式的好处就是不用本地安装Bootstrap，也是不用考虑引用时的路径问题。缺点是担心性能问题，一旦在线样式挂了，那么自己的网站页面样式也就乱掉了。
http://v3.bootcss.com/getting-started/#download
Bootstrap中文网为 Bootstrap 专门构建了自己的免费 CDN 加速服务。
使用方法非常简单：
DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Hello Bootstraptitle>
<link href="http://cdn.bootcss.com/bootstrap/3.2.0/css/bootstrap.min.css" rel="stylesheet">
head>
<body>
<h1>hello Bootstrap<h1>
body>
html>
使用本地的Bootstrap
下载Bootstrap到本地进行解压，解压完成，你将得到一个Bootstrap目录，结构如下：
bootstrap/
├── css/
│ ├── bootstrap.css
│ ├── bootstrap.min.css
│ ├── bootstrap-theme.css
│ └── bootstrap-theme.min.css
├── js/
│ ├── bootstrap.js
│ └── bootstrap.min.js
└── fonts/
├── glyphicons-halflings-regular.eot
├── glyphicons-halflings-regular.svg
├── glyphicons-halflings-regular.ttf
└── glyphicons-halflings-regular.woff
本地调用如下：
DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Hello Bootstraptitle>
<link href="./bootstrap-3.2.0-dist/css/bootstrap.min.css" rel="stylesheet">
<style type='text/css'>
body {
background-color: #CCC;
}
style>
head>
<body>
<h1>hello Bootstrap<h1>
body>
html>
我们多加了一个背景色效果如下：
下面利用Bootstrap的样式编写一个网站出来。
添加导航行栏和登录框
<nav class="navbar navbar-inverse navbar-fixed-top" role="navigation"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar"> <span class="sr-only">Toggle navigationspan> <span class="icon-bar">span> <span class="icon-bar">span> <span class="icon-bar">span> button> <a class="navbar-brand" href="#">首页a> <a class="navbar-brand" href="#">测试a> <a class="navbar-brand" href="#">开发a> div> <div id="navbar" class="navbar-collapse collapse"> <form class="navbar-form navbar-right" role="form"> <div class="form-group"> <input type="text" placeholder="Email" class="form-control"> div> <div class="form-group"> <input type="password" placeholder="Password" class="form-control"> div> <button type="submit" class="btn btn-success">Sign inbutton> form> div> div> nav>
浏览器效果如下：
添加一篇文章
<div class="jumbotron"> <div id='content' class='row-fluid'> <h2>Hello, world!h2> <p class="blog-post-meta">January 1, 2014 by <a href="#">Marka>p> <p>This is a template for a simple marketing or informational website. It includes a large callout called a jumbotron and three supporting pieces of content. Use it as a starting point to create something more unique.p> <p><a class="btn btn-primary btn-lg" role="button">阅读全文 »a>p> div> div>
浏览器效果如下：
添加底部介绍与友情链接
<div class="col-sm-3 col-sm-offset-1 blog-sidebar"> <div class="sidebar-module sidebar-module-inset"> <h4>Abouth4> <p>Etiam porta <em>sem malesuada magnaem> mollis euismod. Cras mattis consectetur purus sit amet fermentum. Aenean lacinia bibendum nulla sed consectetur.p> div> <div class="sidebar-module"> <h4>Elsewhereh4> <ol class="list-unstyled"> <li><a href="#">博客园a>li> <li><a href="#">开源中国a>li> <li><a href="#">infoqa>li> ol> div> div>
最终效果如下：
完整代码：
DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Hello Bootstraptitle>
<link href="./bootstrap-3.2.0-dist/css/bootstrap.min.css" rel="stylesheet">
<style type='text/css'>
body {
background-color: #CCC;
}
style>
head>
<body>
<nav class="navbar navbar-inverse navbar-fixed-top" role="navigation">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
<span class="sr-only">Toggle navigationspan>
<span class="icon-bar">span>
<span class="icon-bar">span>
<span class="icon-bar">span>
button>
<a class="navbar-brand" href="#">首页a>
<a class="navbar-brand" href="#">测试a>
<a class="navbar-brand" href="#">开发a>
div>
<div id="navbar" class="navbar-collapse collapse">
<form class="navbar-form navbar-right" role="form">
<div class="form-group">
<input type="text" placeholder="Email" class="form-control">
div>
<div class="form-group">
<input type="password" placeholder="Password" class="form-control">
div>
<button type="submit" class="btn btn-success">Sign inbutton>
form>
div>
div>
nav>
<div class="jumbotron">
<div id='content' class='row-fluid'>
<h2>Hello, world!h2>
<p class="blog-post-meta">January 1, 2014 by <a href="#">Marka>p>
<p>This is a template for a simple marketing or informational website. It includes a large callout called a jumbotron and three supporting pieces of content. Use it as a starting point to create something more unique.p>
<p><a class="btn btn-primary btn-lg" role="button">阅读全文 »a>p>
div>
div>
<div class="col-sm-3 col-sm-offset-1 blog-sidebar">
<div class="sidebar-module sidebar-module-inset">
<h4>Abouth4>
<p>Etiam porta <em>sem malesuada magnaem> mollis euismod. Cras mattis consectetur purus sit amet fermentum. Aenean lacinia bibendum nulla sed consectetur.p>
div>
<div class="sidebar-module">
<h4>Elsewhereh4>
<ol class="list-unstyled">
<li><a href="#">博客园a>li>
<li><a href="#">开源中国a>li>
<li><a href="#">infoqa>li>
ol>
div>
div>
body>
html>
样式的继承
你一定很好奇，这些样式是怎么玩的？如何你细心的就会留意到div 标签的class属性。
通过class的属性值去继承Bootstrap的样式定义，那么就达到了某种样式效果。
DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8" />
<title>自定义样式title>
<style>
.divcss5-right{width:320px; height:120px;border:1px solid #F00;float:right}
style>
head>
<body>
<div class="divcss5-right">
<h4>友情链接：h4>
<ol class="list-unstyled">
<li><a href="#">博客园a>li>
<li><a href="#">开源中国a>li>
<li><a href="#">infoqa>li>
ol>
div>
body>
html>
玩前端就是要不断的修改里面的属性或信息，然后看浏览器上的展示效果。