JS判断滚动到屏幕底部

mounted() {
            window.onscroll = function () {
                //变量scrollTop是滚动条滚动时，距离顶部的距离
                var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
                //变量windowHeight是可视区的高度
                var windowHeight = document.documentElement.clientHeight || document.body.clientHeight;
                //变量scrollHeight是滚动条的总高度
                var scrollHeight = document.documentElement.scrollHeight || document.body.scrollHeight;
                //滚动条到底部的条件
                if (scrollTop + windowHeight == scrollHeight) {
                    if (vuedata.has_more) {
                        vuedata.page++;
                        vm.getList();
                    }
                }
            }
        },