页面加载进度条的实现

https://loading.io ------ 进度条小图标的制作网站

通过加载状态事件制作进度条：
document.onreadystatechange页面加载状态改变时的事件；
document.readyState返回当前文档的状态（uninitialized--还未开始载入；loading--载入中；interactive--已加载，文档与用户可以开始交互；complete--载入完成）

e.g.<!DOCTYPE ht<html lang="en">

<head>

    <meta charset="UTF-8">
    <title>进度条2</title>
    <style type="text/css">   //添加进度条的样式
        .loading{
             100%;
            height: 100%;
            position: fixed;
            left: 0;
            top: 0;
            z-index: 100;
            background: #ffffff;

        }
        .loading .pic{
             64px;
            height: 64px;
            border: 1px solid red;
            background: url("images/loading.gif");
            /*剧中显示*/
            position: absolute;
            top: 0;
            bottom: 0;
            left: 0;
            right: 0;
            margin: auto;
        }
    </style>
//引入jquery包
    <script type="text/javascript" src="jquery-1.3.1.js"></script>
    <script type="text/javascript">
//        页面加载状态改变时的事件
       document.onreadystatechange = function () {
           if(document.readyState == 'complete'){   //判断页面加载完成，加载的图标就隐藏
               $(".loading").fadeOut();
           }
       }
    </script>
</head>
<body>
    <div class="loading">
        <div class="pic"></div>  //加载图标的显示
    </div>
    <img src="http://pic29.nipic.com/20130514/12477194_083818249176_2.jpg" alt="">
    <img src="http://pic37.nipic.com/20140115/9448607_120900609000_2.jpg" alt="">
    <img src="http://pic.58pic.com/58pic/11/15/53/43g58PICz9B.jpg" alt="">
    <img src="http://pic3.nipic.com/20090519/2390580_090051082_2.jpg" alt="">
    <img src="http://pic25.nipic.com/20121127/9026859_131523397124_2.jpg" alt="">
    <img src="http://pic29.nipic.com/20130514/12477194_083818249176_2.jpg" alt="">
</body>
</html>