网页进度条制作
一、为什么需要网页进度条
随着HTML的普及，各种CSS3动画及特效在网页中层出不穷，PC端载入数据的速度还算可以，移动端相对要慢很多，如果图片或脚本没有完全载入，用户在操作中可能发生各种问题，因此我们需要对载入数据进行检测，以更加人性化的方式给用户展现。
二、常见进度条的样式
百分比形式旋转动画固定在顶部的线条三、进度条制作
加载进度条的制作，需要通过加载状态事件，才是正确的结合实际情况的做法。
需要使用的方法：
document.onreadystatechange 页面加载状态改变时的事件document.readystate 返回文档当前的状态状态值：
uninitialized 还未开始载入loading 载入中interactive 已加载，文档与用户开始交互complete 载入完成四、具体代码
CSS样式文件
/* 加载动画样式start */.loading {width: 100%;height: 100%;position: fixed;top: 0;left: 0;z-index: 100;background: #ffffff;}.loading .picture {position: absolute;top: 0;left: 0;bottom: 0;right: 0;margin: auto;background: url(img/loading.gif);width: 150px;height: 150px;}/* 加载动画样式end */
js文件（重要）
<script src="/jquery-3.1.1.min.js" type="text/javascript" charset="utf-8"></script><script type="text/javascript">document.onreadystatechange = function() {console.log(document.readyState)if (document.readyState == 'complete') {console.log(document.readyState, '11111111111')$('.loading').fadeOut();}}</script>
五、步骤总结
首先，我们在 htm l文件中定义 loading 的结构；而后，在 css 文件中书写对应的样式文件；最后，在 js 文件中，我们使用 onreadystatechange 在时机中，我们通过判断 readyState 的值，决定隐藏 loading 结构的隐藏即可。六、完整代码分享
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>进度条动画制作</title><style type="text/css">* {margin: 0;padding: 0;}/* 加载动画样式start */.loading {width: 100%;height: 100%;position: fixed;top: 0;left: 0;z-index: 100;background: #ffffff;}.loading .picture {position: absolute;top: 0;left: 0;bottom: 0;right: 0;margin: auto;background: url(img/loading.gif);width: 150px;height: 150px;}/* 加载动画样式end *//* 页面样式start */.container {width: 1200px;margin: 100px auto;border: 1px solid red;padding: 20px;overflow: hidden;border-radius: 10px;}.container .item {float: left;margin-bottom: 10px;}.container img {font-size: 0;vertical-align: middle;width: 300px;height: 200px;}/* 页面样式end */</style></head><body><div class="loading"><div class="picture"></div></div><!-- 注意：以下结构仅仅是为了演示页面而已 --><div class="container"><div class="item"><img src="/wallpaper/-01-06/5a50674a7b626.jpg"></div><div class="item"><img src="http://img2./it/u=2398464402,4254570216&fm=11&gp=0.jpg"></div><div class="item"><img src="/bfs/article/669b74844e47c4ca9774aad43dc62b0d879fbcd6.jpg"></div><div class="item"><img src="/wallpaper/-06-08/5b1a448a79175.jpg"></div><div class="item"><img src="http://img0./it/u=228361023,682353921&fm=26&gp=0.jpg"></div><div class="item"><img src="http://img5./it/u=550633143,1906543664&fm=11&gp=0.jpg"></div><div class="item"><img src="/flower/digital_flower_jp_03/wallpapers/1680x1050/_Digital_Flower_Photo_321.jpg"></div><div class="item"><img src="/nature/_Landscape_1680_Desktop_04/wallpapers/1680x1050/Rising%20Mist%20at%20Dawn.jpg"></div><div class="item"><img src="/photograph/Fresh%20Vegetables%20by%20Isabelle%20Rozenbaum/wallpapers/1440x900/Bunch%20of%20radishes%2C%20close-up.jpg"></div><div class="item"><img src="/desk/1208/2044/ntk-2044-14905.jpg"></div><div class="item"><img src="/cartoon/Semafore_Calendar_Project_1920/wallpapers/1280x800/Calendar_Design_.04.jpg"></div><div class="item"><img src="/cartoon/future_tech_background/wallpapers/1680x1050/%5Bwallcoo_com%5D_3516_future_TECH_Image.jpg"></div><div class="item"><img src="/images/piclib/05/20/batch/1/176010/13690210721960gaa56pug9.jpg"></div><div class="item"><img src="/desk/1207/1030/ntk119230.jpg"></div><div class="item"><img src="/desk/1207/1041/ntk120340.jpg"></div><div class="item"><img src="http://g./zhidao/pic/item/6a600c338744ebf814066acedbf9d72a6159a7cf.jpg"></div><div class="item"><img src="/wallpaper/3/510b709821ec1.jpg"></div><div class="item"><img src="/gfox/wallpaper//06/1920x1200.jpg"></div><div class="item"><img src="/0825/668573_135507057246_2.jpg"></div><div class="item"><img src="/wallpaper/a/51f1e196b5576.jpg"></div><div class="item"><img src="http://img2./it/u=3757609547,3947405383&fm=214&gp=0.jpg"></div><div class="item"><img src="http://img4./it/u=2295877184,3273384647&fm=214&gp=0.jpg"></div><div class="item"><img src="/bfs/article/9a3129c90c5da974176a74b4bbe782f1253fb8d2.jpg"></div><div class="item"><img src="/bfs/article/d6d373a850c45beb250a7cbdcab1176551206740.jpg@1320w_934h.jpg"></div><div class="item"><img src="/bfs/article/5350896be8e02fa2e673591380956fbf884a9e76.jpg"></div><div class="item"><img src="/bfs/article/5278e12727d1ccd794a1c990905675e9b9992cce.jpg"></div><div class="item"><img src="http://img./upload/club/other//6/4/nrq_1149351040.jpg"></div><div class="item"><img src="/wallpaper/1/5791e7b252e81.jpg"></div></div></body></html><script src="/jquery-3.1.1.min.js" type="text/javascript" charset="utf-8"></script><script type="text/javascript">document.onreadystatechange = function() {console.log(document.readyState)if (document.readyState == 'complete') {console.log(document.readyState, '11111111111')$('.loading').fadeOut();}}</script>
