<iframe src="~/Files/3.html" id="iframepage" width="825" onload="func()"></iframe>
<script type="text/javascript">
function func() {
var ifm = document.getElementById("iframepage");
ifm.height = window.document.body.clientHeight - 100;
}
<!--在chrome有兼容問題，FF和IE10無問題，網上說chrome訪問iframe要在服務器環境下，不知道什么情況-->
window.document.getElementById("iframepage").contentWindow.onscroll = function aaa() {
var ifm = document.getElementById("iframepage").contentWindow.document.documentElement;
if (ifm.scrollTop == ifm.scrollHeight - ifm.clientHeight) {
alert("到底了");
}

}
</script>