如果您可以控制iframe内容，我强烈建议使用

调整观察者大小

只需在iframe的srcdoc属性的末尾插入以下内容， 如果需要，可以转义。

<script type="text/javascript">
var ro = new ResizeObserver(entries => {
  for (let entry of entries) {
    const cr = entry.contentRect;
    // console.log(window.frameElement);
    window.frameElement.style.height =cr.height +30+ "px";
  }
});

ro.observe(document.body);
</script>

This is slightly tricky as you have to know when the iframe page has loaded, which is difficuly when you're not in control of its content. Its possible to add an onload handler to the iframe, but I've tried this in the past and it has vastly different behaviour across browsers (not guess who's the most annoying...). You'd probably have to add a function to the iframe page that performs the resize and inject some script into the content that either listens to load events or resize events, which then calls the previous function. I'm thinking add a function to the page since you want to make sure its secure, but I have no idea how easy it will be to do.

最后，我找到了一些其他的解决方案，从iframe使用窗口发送数据到父网站。postMessage(消息、targetOrigin);。下面我来解释一下我是怎么做到的。

站点A = http://foo.com 站点B = http://bar.com

sitb在网站内部加载

SiteB网站有这条线

window.parent.postMessage("Hello From IFrame", "*"); 

or

window.parent.postMessage("Hello From IFrame", "http://foo.com");

然后site ea有如下代码

// Here "addEventListener" is for standards-compliant web browsers and "attachEvent" is for IE Browsers.
var eventMethod = window.addEventListener ? "addEventListener" : "attachEvent";
var eventer = window[eventMethod];


var messageEvent = eventMethod == "attachEvent" ? "onmessage" : "message";

// Listen to message from child IFrame window
eventer(messageEvent, function (e) {
   alert(e.data);
   // Do whatever you want to do with the data got from IFrame in Parent form.
}, false); 

如果你想添加安全连接，你可以在事件输入中使用这个If条件(messageEvent, function (e) {})

if (e.origin == 'http://iframe.example.com') {
    alert(e.data); 
    // Do whatever you want to do with the data got from IFrame in Parent form.
}

对于IE

IFrame内:

 window.parent.postMessage('{"key":"value"}','*');

外:

 eventer(messageEvent, function (e) {
   var data = jQuery.parseJSON(e.data);
   doSomething(data.key);
 }, false);

使用jquery加载(跨浏览器):

 <iframe src="your_url" marginwidth="0"  marginheight="0" scrolling="No" frameborder="0"  hspace="0" vspace="0" id="containiframe" onload="loaderIframe();" height="100%"  width="100%"></iframe>

function loaderIframe(){
var heightIframe = $('#containiframe').contents().find('body').height();
$('#frame').css("height", heightFrame);
 }  

在响应式页面中调整大小:

$(window).resize(function(){
if($('#containiframe').length !== 0) {
var heightIframe = $('#containiframe').contents().find('body').height();
 $('#frame').css("height", heightFrame);
}
});

使用jQuery的最简单方法:

$("iframe")
.attr({"scrolling": "no", "src":"http://www.someotherlink.com/"})
.load(function() {
    $(this).css("height", $(this).contents().height() + "px");
});

我相信这样的做法会奏效。

parent.document.getElementById(iFrameID).style.height=framedPage.scrollHeight;

在iframe内容中加载你的body。