经常，我们在浏览各种网页的时候，都会有各种动画效果展示，像下图所示的是很多网上商城常用的货品展示方式，同类的货品并排展现在窗口上，用户如果看中了哪一款商品想要查看详情的话，只要将鼠标放上该商品的区域，原本折叠起来的商品便会自动展开，详情便会展现在用户面前，而这一动画，就是利用了DOM+JS结合来实现的，今天的小练习就是要实现这个效果。
首先，先将页面基本的框架用html实现，将四张图封装在了一个名为“container”的div块中
<!doctype html> <meta charset="UTF-8"> <html> <head> <title> 鼠标滑过页面自动变大 </title> <link href="https://www.jb51.net/styles/reset.css" /> <link href="https://www.jb51.net/styles/slidingdoors.css" /> <script src="https://www.jb51.net/slidlingdoors.js"></script> </head> <body> <div> <img src="https://www.jb51.net/article/images/door1.png"/> <img src="https://www.jb51.net/article/images/door2.png"/> <img src="https://www.jb51.net/article/images/door3.png"/> <img src="https://www.jb51.net/article/images/door4.png"/> </div> </body> </html>
接着，我将大体的样式用了两个样式表修饰如下：
依次为
slidingdoors.css和reset.css: #container { height: 477px; margin: 0 auto; border-right: 1px solid #ccc; border-bottom: 1px solid #ccc; overflow: hidden; position: relative; } #container img { position: absolute; display: block; left: 0; border-left: 1px solid #ccc; }
/** * Eric Meyer's Reset CSS v2.0 () * */ html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video { margin: 0; padding: 0; border: 0; font-size: 100%; font: inherit; vertical-align: baseline; } /* HTML5 display-role reset for older browsers */ article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section { display: block; } body { line-height: 1; } ol, ul { list-style: none; } blockquote, q { quotes: none; } blockquote:before, blockquote:after, q:before, q:after { content: ''; content: none; } table { border-collapse: collapse; border-spacing: 0; }
接下来，就要实现滑动效果了，js代码如下：
window.onload=function(){ var box=document.getElementById("container"); var imgs=box.getElementsByTagName("img"); var imgwidth=imgs[0].offsetWidth; var exposewidth=160; var boxwidth=imgwidth+exposewidth*(imgs.length-1); box.style.width=boxwidth+'px'; function setImgPos(){ for(var i=1;i<imgs.length;i++) { imgs[i].style.left=imgwidth+exposewidth*(i-1)+'px'; } } setImgPos(); var translate=imgwidth-exposewidth; for(var i=0;i<imgs.length;i++) { (function(i){ imgs[i].onmouseover=function(){ setImgPos(); for(var j=1;j<=i;j++) { imgs[j].style.left=parseInt(imgs[j].style.left,10)-translate+'px'; } }; })(i); } };
弄好后的效果图如下：
遇到的问题：
1.图片复位函数中i、j变量傻傻分不清；
2.做出来的效果一张图片复位后把其余未复位图片都挡住了，主要是复位函数出了小问题。
经验：js函数变量复杂，逻辑严谨，写代码时一定要谨慎小心