1、代码如下：
<!DOCTYPE html><html>
<head>
<meta charset="UTF-8">
<title>Test_Scroll_Bar_js</title>
<meta name="viewport" content="width=device-width, user-scalable=no">
</head>
<body>
<div id="part1" style="height:1000px;overflow: auto;background: lightyellow;"></div>
<div id="part2" style="height:1000px;overflow: auto;background:lightgreen;"></div>
<script>
var d = document.getElementById("part1").offsetHeight;
console.info(d);
window.addEventListener("scroll", function(event) {
var scrollTop = document.documentElement.scrollTop || window.pageYOffset || document.body.scrollTop;
console.log(scrollTop);
if(document.documentElement.scrollHeight == document.documentElement.clientHeight + scrollTop ) {
alert("Touch_Buttom!");
}
});
</script>
</body>
</html>
2、滚动鼠标轮，向下浏览。
3、到达末端弹出窗口说明已经到达底部。
