JS - 移动端滚动穿透

var ModalHelper = (function(bodyCls) {
    var scrollTop;
    return {
        //使body不可滚动
        afterOpen: function() {
            scrollTop = document.scrollingElement.scrollTop;
            document.body.classList.add(bodyCls);
            document.body.style.top = -scrollTop + 'px';
        },
        //使body恢复滚动
        beforeClose: function() {
            document.body.classList.remove(bodyCls);
            document.scrollingElement.scrollTop = scrollTop;
        }
    };
})('modal-open');

参考