jquery 延迟加载

/*
* jquery.scrollLoading.js
* 2010-11-19 v1.0
*/
(function ($) {
$.fn.scrollLoading = function (options) {
var defaults = {
attr: "data-url"
};
var params = $.extend({}, defaults, options || {});
params.cache = [];
$(this).each(function () {
var node = this.nodeName.toLowerCase(), url = $(this).attr(params["attr"]);
if (!url) { return; }
//重组
var data = {
obj: $(this),
tag: node,
url: url
};
params.cache.push(data);
});

//动态显示数据
var loading = function () {
var st = $(window).scrollTop(), sth = st + $(window).height();
$.each(params.cache, function (i, data) {
var o = data.obj, tag = data.tag, url = data.url;
if (o) {
post = o.position().top;
if (post < 10)
post = o.offset().top;
posb = post + o.height();

if ((post > st && post < sth) || (posb > st && posb < sth)) {
//在浏览器窗口内

if (tag === "img") {
//图片，改变src
o.attr("src", url);
} else if (tag == "iframe") {
o.attr("src", url);
} else if (tag == "span") {
eval(url);
}
else {
o.load(url);
}
data.obj = null;
}
}
});
return false;
};

//事件触发
//加载完毕即执行
loading();
//滚动执行
$(window).bind("scroll", loading);
};
})(jQuery);

 

需先引入jquery.js

用法：

$(function () {
$('img').scrollLoading();
});