我需要检测用户是否滚动到页面底部。如果它们在页面的底部，当我在底部添加新内容时，我会自动将它们滚动到新的底部。如果他们不在底部，他们正在阅读页面上更高的先前内容，所以我不想自动滚动他们，因为他们想呆在那里。
我如何检测用户是否滚动到页面的底部，或者他们是否在页面上滚动得更高?
当前回答
如果你用其他方法都不走运，试试这个方法。
窗口。Onscroll = function() { const difference = document.documentElement.scrollHeight - window.innerHeight; const scrollposition = document.documentElement.scrollTop; If (difference - scrollposition <= 2) { alert(“页底!”); ｝ ｝
其他回答
令人惊讶的是，没有一个解决方案对我有效。我认为这是因为我的css是混乱的，和身体没有围绕所有的内容使用高度:100%(不知道为什么)。然而，在寻找解决方案时，我想到了一些东西……基本上是一样的，但也许值得一看——我是编程新手，所以抱歉，如果它做同样的事情更慢，支持更少或类似的事情……
window.onscroll = function(evt) {
var check = (Element.getBoundingClientRect().bottom - window.innerHeight) <= 0;
if (check) { console.log("You're at the bottom!"); }
};
window.onscroll = function(ev) {
if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight) {
// you're at the bottom of the page
}
};
看到演示
使用defaultView和documentElement嵌入功能代码片段:
const {defaultView} =文档; const {documentElement} =文档; const handler = evt => (() => { const hitBottom = (() => (defaultView.)innerHeight + defaultView.pageYOffset) >= documentElement.offsetHeight)(); hitBottom ？ console.log(“是的”) : console.log(“不”) })； 文档。addEventListener(“滚动”,处理程序); <pre style="height:110vh;background-color:fuchsia">向下滚动</pre>
我一直在寻找答案，但还没有找到确切的答案。这是一个纯javascript解决方案，与最新的Firefox, IE和Chrome在这个答案的时间:
// document.body.scrollTop alone should do the job but that actually works only in case of Chrome.
// With IE and Firefox it also works sometimes (seemingly with very simple pages where you have
// only a <pre> or something like that) but I don't know when. This hack seems to work always.
var scrollTop = (document.documentElement && document.documentElement.scrollTop) || document.body.scrollTop;
// Grodriguez's fix for scrollHeight:
// accounting for cases where html/body are set to height:100%
var scrollHeight = (document.documentElement && document.documentElement.scrollHeight) || document.body.scrollHeight;
// >= is needed because if the horizontal scrollbar is visible then window.innerHeight includes
// it and in that case the left side of the equation is somewhat greater.
var scrolledToBottom = (scrollTop + window.innerHeight) >= scrollHeight;
// As a bonus: how to scroll to the bottom programmatically by keeping the horizontal scrollpos:
// Since window.innerHeight includes the height of the horizontal scrollbar when it is visible
// the correct vertical scrollTop would be
// scrollHeight-window.innerHeight+sizeof(horizontal_scrollbar)
// Since we don't know the visibility/size of the horizontal scrollbar
// we scroll to scrollHeight that exceeds the value of the
// desired scrollTop but it seems to scroll to the bottom with all browsers
// without problems even when the horizontal scrollbar is visible.
var scrollLeft = (document.documentElement && document.documentElement.scrollLeft) || document.body.scrollLeft;
window.scrollTo(scrollLeft, scrollHeight);
我刚刚开始看这个，这里的答案帮助了我，所以谢谢你。 我稍微扩展了一下，这样代码就可以安全地回到IE7:
希望这对某些人有用。
来，来一把小提琴吧。
<!DOCTYPE html>
<html>
<head>
<style>
div {
height: 100px;
border-bottom: 1px solid #ddd;
}
div:nth-child(even) {
background: #CCC
}
div:nth-child(odd) {
background: #FFF
}
</style>
</head>
<body>
<div></div><div></div><div></div><div></div><div></div><div></div><div></div>
<div></div><div></div><div></div><div></div><div></div><div></div><div></div>
<div></div><div></div><div></div><div></div><div></div><div></div><div></div>
<div></div><div></div><div></div><div></div><div></div><div></div><div></div>
<div></div><div></div><div></div><div></div><div></div><div></div><div></div>
</body>
<script type="text/javascript">
console.log("Doc Height = " + document.body.offsetHeight);
console.log("win Height = " + document.documentElement.clientHeight);
window.onscroll = function (ev) {
var docHeight = document.body.offsetHeight;
docHeight = docHeight == undefined ? window.document.documentElement.scrollHeight : docHeight;
var winheight = window.innerHeight;
winheight = winheight == undefined ? document.documentElement.clientHeight : winheight;
var scrollpoint = window.scrollY;
scrollpoint = scrollpoint == undefined ? window.document.documentElement.scrollTop : scrollpoint;
if ((scrollpoint + winheight) >= docHeight) {
alert("you're at the bottom");
}
};
</script>
</html>
