图片延迟加载

<script src="http://s0.ifengimg.com/static/js/jquery-1.7.2.min_c4de8813.js"></script>
<script src="http://s0.ifengimg.com/static/js/lazyload_636d11f9.js"></script>
<script>
var lazy = lazyload({
container: document.body,
offset: 100,
src: 'data-original' // or function(elt) { return customSrc }
});
</script>

<img class="lazy" src='data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==' onload="lazy(this)" data-original="http://s0.ifengimg.com/2016/08/29/img9_31b67215.jpg" height="2000" alt=""/>