html纯js实现图片懒加载 

html纯js实现图片懒加载案例代码下载地址：http://www.jiajiajia.club/file/info/JA67P0/123

<script>
    window.onload = function(){
        //imgs是目标区域的所有img标签集合
        var imgs=document.getElementsByTagName("img");
        var imgDatas=new Array();
        for(var i=0;i<imgs.length;i++){
            if(imgs[i].getAttribute("data-src")!=null){
                imgDatas[i]=imgs[i];
            }
        }
        function lazyload(){
            var h = window.innerHeight;
            var s = document.documentElement.scrollTop || document.body.scrollTop;
            for(var i=0;i<imgDatas.length;i++){
                if ((h+s)>imgDatas[i].offsetTop) {
                    imgDatas[i].src = imgDatas[i].getAttribute('data-src')
                    imgDatas.splice(i,1);
                }
            }
        }
        lazyload();
        window.onscroll =function(){
            lazyload();
        }
    }
</script>