无聊，不想用 jquery lazyload，自己手工写了个简短代码，欢迎批评指正收藏

(function () {
    var sign = "lazy";
    var imgsArray = [];
    var imgs = document.getElementsByTagName('img');
    for (var i = 0; i < imgs.length; i++) {
        var img = imgs[i];
        var dsrc = img.getAttribute('data-src');
        var cname = img.className;
        if (cname && cname.indexOf(sign) >= 0 && dsrc && img.src != dsrc) {
            imgsArray.push(img);
        }
    }
    var b = document.body;
    var loadAreaImages = function () {
        var bst = b.scrollTop;
        var bsl = b.scrollLeft;
        var ih = window.innerHeight;
        var iw = window.innerWidth;
        for (var i = 0; i < imgsArray.length; i++) {
            var img = imgsArray[i];
            var dsrc = img.getAttribute('data-src');
            if (dsrc && img.src != dsrc) {
                var iot = img.offsetTop;
                var iol = img.offsetLeft;
                if (ih + bst + 100 >= iot && iw + bsl + 100 >= iol && bst - 100 <= iot && bsl - 100 <= iol) {
                    img.src = dsrc;
                }
            }
        }
    }
    var lst = null;
    var loadImages = function () {
        if (lst) {
            clearTimeout(lst);
        }
        lst = setTimeout(loadAreaImages, 500);
    }
    var bind = function (e, f) {
        var l = window.addEventListener;
        var w = window.attachEvent;
        l ? l(e, f, true) : w('on' + e, f);
    }
    var eves = ['load', 'scroll', 'resize'];
    for (var e in eves)
        bind(eves[e], loadImages, true);
})();