在Web页面中实现Bootstrap滚动监控器其实非常简单,接下来我们一步一步来看滚动监控器是如何设计的。
第一步:使用滚动监控器,首要的条件是在页面中加载对应的插件。在这里你可以加载合并好的bootstrap.js或者其独立的插件文件scrollspy.js。这里以加载合并好的js为例:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
第二步:设计一个带有下拉菜单的导航条。分别为导航条和下拉菜单项定义一个锚点链接,锚点分别为“#blog”,“html”,“#css”,“#sass”,“#js”,“php”,“#about”。同时为导航条定义一个id值“navbar-menu”(id名称可自由定义),方便滚动监控。
第三步:设计监控对象。这里将监控对象内容都放置在一个div名为scrollspy(这个类名可自由定义)的容器中,其中放了多个子内容框。每个子内容框有一个标题,而且每个标题的ID值与导航菜单项中的锚点链接名相对应,并且注意加入“data-target="#navbar-menu"”属性(这个属性值要与前面的nav标签的id名称保持一致)
<div class="scrollspy" data-target="#navbar-menu"> <h4 id="blog">Blog</h4> <p>…</p> <h4 id="html">Html</h4> <p>…</p> <h4 id="css">CSS</h4> <p>…</p> <h4 id="sass">Sass</h4> <p>…</p> <h4 id="js">JavaScript</h4> <p>…</p> <p>…</p> <h4 id="php">PHP</h4> <p>…</p> <p>…</p> <h4 id="about">About</h4> <p>…</p> <p>…</p> </div>
第四步:为监控对象定义样式,设置容器scrollspy大小(设置高度目的是为了产生垂直滚动条)。
.scrollspy{ height:500px; font-size:20px; overflow:auto; }
我来试试:补充缺少代码
右侧代码只是实现了锚点跳转功能,但没有实现“滚动监控器”功能,补充右侧编辑器缺少的代码以实现滚动监控器的功能。
注意:补充49行???区代码。
<!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>下拉菜单--属性声明式方法(一)</title> <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css"> <style> .scrollspy-example{ height:500px; font-size:20px; overflow:auto; } </style> </head> <body> <div class="bs-docs-section"> <h1 class="page-header" id="scrollspy">ScrollSpy <small>scrollspy.js</small></h1> <h2 id="scrollspy-examples">Example in navbar</h2> <p>The ScrollSpy plugin is for automatically updating nav targets based on scroll position. Scroll the area below the navbar and watch the active class change. The dropdown sub items will be highlighted as well.</p> <div class="bs-example"> <nav role="navigation" class="navbar navbar-default navbar-static" id="navbar-example2"> <div class="container-fluid"> <div class="navbar-header"> <button data-target=".bs-example-js-navbar-scrollspy" data-toggle="collapse" type="button" class="navbar-toggle collapsed"> <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">Project Name</a> </div> <div class="collapse navbar-collapse bs-example-js-navbar-scrollspy"> <ul class="nav navbar-nav"> <li><a href="#fat">@fat</a></li> <li><a href="#mdo">@mdo</a></li> <li class="dropdown"> <a aria-expanded="false" role="button" data-toggle="dropdown" class="dropdown-toggle" id="navbarDrop1" href="#">Dropdown <span class="caret"></span></a> <ul aria-labelledby="navbarDrop1" role="menu" class="dropdown-menu"> <li><a tabindex="-1" href="#one">one</a></li> <li><a tabindex="-1" href="#two">two</a></li> <li class="divider"></li> <li><a tabindex="-1" href="#three">three</a></li> </ul> </li> </ul> </div> </div> </nav> <div class="scrollspy-example" data-offset="0" data-target="???" data-spy="scroll"> <h4 id="fat">@fat</h4> <p>Ad leggings keytar, brunch id art party dolor labore. Pitchfork yr enim lo-fi before they sold out qui. Tumblr farm-to-table bicycle rights whatever. Anim keffiyeh carles cardigan. Velit seitan mcsweeney's photo booth 3 wolf moon irure. Cosby sweater lomo jean shorts, williamsburg hoodie minim qui you probably haven't heard of them et cardigan trust fund culpa biodiesel wes anderson aesthetic. Nihil tattooed accusamus, cred irony biodiesel keffiyeh artisan ullamco consequat.</p> <h4 id="mdo">@mdo</h4> <p>Veniam marfa mustache skateboard, adipisicing fugiat velit pitchfork beard. Freegan beard aliqua cupidatat mcsweeney's vero. Cupidatat four loko nisi, ea helvetica nulla carles. Tattooed cosby sweater food truck, mcsweeney's quis non freegan vinyl. Lo-fi wes anderson +1 sartorial. Carles non aesthetic exercitation quis gentrify. Brooklyn adipisicing craft beer vice keytar deserunt.</p> <h4 id="one">one</h4> <p>Occaecat commodo aliqua delectus. Fap craft beer deserunt skateboard ea. Lomo bicycle rights adipisicing banh mi, velit ea sunt next level locavore single-origin coffee in magna veniam. High life id vinyl, echo park consequat quis aliquip banh mi pitchfork. Vero VHS est adipisicing. Consectetur nisi DIY minim messenger bag. Cred ex in, sustainable delectus consectetur fanny pack iphone.</p> <h4 id="two">two</h4> <p>In incididunt echo park, officia deserunt mcsweeney's proident master cleanse thundercats sapiente veniam. Excepteur VHS elit, proident shoreditch +1 biodiesel laborum craft beer. Single-origin coffee wayfarers irure four loko, cupidatat terry richardson master cleanse. Assumenda you probably haven't heard of them art party fanny pack, tattooed nulla cardigan tempor ad. Proident wolf nesciunt sartorial keffiyeh eu banh mi sustainable. Elit wolf voluptate, lo-fi ea portland before they sold out four loko. Locavore enim nostrud mlkshk brooklyn nesciunt.</p> <h4 id="three">three</h4> <p>Ad leggings keytar, brunch id art party dolor labore. Pitchfork yr enim lo-fi before they sold out qui. Tumblr farm-to-table bicycle rights whatever. Anim keffiyeh carles cardigan. Velit seitan mcsweeney's photo booth 3 wolf moon irure. Cosby sweater lomo jean shorts, williamsburg hoodie minim qui you probably haven't heard of them et cardigan trust fund culpa biodiesel wes anderson aesthetic. Nihil tattooed accusamus, cred irony biodiesel keffiyeh artisan ullamco consequat.</p> <p>Keytar twee blog, culpa messenger bag marfa whatever delectus food truck. Sapiente synth id assumenda. Locavore sed helvetica cliche irony, thundercats you probably haven't heard of them consequat hoodie gluten-free lo-fi fap aliquip. Labore elit placeat before they sold out, terry richardson proident brunch nesciunt quis cosby sweater pariatur keffiyeh ut helvetica artisan. Cardigan craft beer seitan readymade velit. VHS chambray laboris tempor veniam. Anim mollit minim commodo ullamco thundercats. </p> </div> </div><!-- /example --> </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>