图片懒加载

<img data-src='路径'/>



window.addEventListener('load', function () {
    var imgs = document.querySelectorAll('img');
    img = Array.from(imgs);
    console.log(img);
    var h = document.documentElement.clientHeight||document.body.clientHeight;

    var scrollTop = 0
    window.onscroll = function () {
        scrollTop = document.documentElement.scrollTop||document.body.scrollTop;


        // console.log(scrollTop);

        for (var i = 0; i < imgs.length; i++) {
            var offsetTop = imgs[i].offsetTop;
            if (offsetTop < h + scrollTop) {
                imgs[i].src = imgs[i].dataset.src
            }

        }
    }
    for (var i = 0; i < imgs.length; i++) {
        var offsetTop = imgs[i].offsetTop;
        if (offsetTop < h + scrollTop) {
            imgs[i].src = imgs[i].dataset.src
        }

    }
})