js determines whether the web page in the iframe scrolls to the bottom triggers the event

There was a requirement before that to determine whether the web page in the iframe scrolled to the bottom to trigger the event. I found a lot of information online, which was said to be under the current page, so I simply studied it myself and found a solution.

clientHeight: The height of this element, the height that occupies the entire space

offsetHeight: refers to the height of the element content

scrollTop: It can be understood as the length of the scroll bar that can be scrolled

The following is the source code

The code copy is as follows:

<iframe src="~/Files/3.html" id="iframepage" onload="func()"></iframe>

<script type="text/javascript">

function func() {

var ifm = document.getElementById("iframepage");

ifm.height = window.document.body.clientHeight - 100;

}

<!--There are compatibility issues in chrome, and there is no problem with FF and IE10. It is said online that chrome accesses iframes in a server environment, and I don’t know what the situation is-->

window.document.getElementById("iframepage").contentWindow.onscroll = function aaa() {

var ifm = document.getElementById("iframepage").contentWindow.document.documentElement;

if (ifm.scrollTop == ifm.scrollHeight - ifm.clientHeight) {

alert("The end");

}

}

</script>