下面是代码，这是伪加载提示条，跟加载速度无关
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<style type="text/css">
.current a {
font-size: 20px;
}
.over {
display: block;
position: absolute;
top: 250px;
left: 0;
100%;
height: 700px;
background-color: white;
opacity:0.5;
z-index: 1000;
}
.layout {
display: block;
position: absolute;
top: 20%;
left: 20%;
20%;
height: 20%;
z-index: 1001;
text-align:center;
}
</style>
<script type="text/javascript">
setTimeout(showMain,"2700");
function showMain()
{
document.getElementById("over").style.display = "none";
document.getElementById("layout").style.display = "none";
}
</script>
</head>
<body>
<div class="current"><a href="#" onclick="showMain()">Loading</a></div>
<div id="over" class="over"></div>
<div id="layout" class="layout"><img src="loading.gif" /></div>
</body>
</html>
下面是网上其他人的解决方法，可以真正实现显示加载的百分比
如果需要在页面初始加载时显示加载进度。主要是指图片很多的情况下：
可以使用第三方Jquery插件jquery.imgpreload.min.js
调用里面的方法：imgpreload即可，实例如下：
var imgNum = 0;
var images = [];
$(function(){ preloadImg(); });
//里面有两种方式
function preLoadImg() {
//第一种方式：通过dom方法获取页面中的所有img，包括<img>标签和css中的background-image
/*get all imgs those tag is <img>
var imgs = document.images;
for (var i = 0; i < imgs.length; i++) {
images.push(imgs[i].src);
}
//get all images in style
var cssImages = getallBgimages();
for (var j = 0; j < cssImages.length; j++) {
images.push(cssImages[j]);
}*/
//第二种方式：把所有该网页上用到的图片文件都预先放入一个数组里
$.imgpreload(['images/bg1.jpg', 'images/bg2.jpg'], function () {
//此处是显示进度百分比时需要用到的背景图，这个可以先加载进去
});
//then push all other images in array to load
images.push("images/test_1.png");
images.push("images/test_2.png");
images.push("images/test_3.png");
//。。。
images.push("images/test_n.png");
/*这里是真正的图片预加载 preload*/
$.imgpreload(images,
{
each: function () {
/*this will be called after each image loaded*/
var status = $(this).data('loaded') ? 'success' : 'error';
if (status == "success") {
var v = (parseFloat(++imgNum) / images.length).toFixed(2);
$("#percentShow").html(Math.round(v * 100) + "<sup>%</sup>");
}
},
all: function () {
/*this will be called after all images loaded*/
$("#percentShow ").html("100<sup>%</sup>");
$("percentShow").fadeOut(1000);
$(".main").show();
}
});
}
//get all images in style（此方法引用其他博客的）
function getallBgimages() {
var url, B = [], A = document.getElementsByTagName('*');
A = B.slice.call(A, 0, A.length);
while (A.length) {
url = document.deepCss(A.shift(), 'background-image');
if (url) url = /url(['"]?([^")]+)/.exec(url) || [];
url = url[1];
if (url && B.indexOf(url) == -1) B[B.length] = url;
}
return B;
}
document.deepCss = function (who, css) {
if (!who || !who.style) return '';
var sty = css.replace(/-([a-z])/g, function (a, b) {
return b.toUpperCase();
});
if (who.currentStyle) {
return who.style[sty] || who.currentStyle[sty] || '';
}
var dv = document.defaultView || window;
return who.style[sty] ||
dv.getComputedStyle(who, "").getPropertyValue(css) || '';
}
Array.prototype.indexOf = Array.prototype.indexOf ||
function (what, index) {
index = index || 0;
var L = this.length;
while (index < L) {
if (this[index] === what) return index;
++index;
}
return -1;
}