问题
Is it possible to tell if the source of an iFrame has redirected the client to another page? And if so, tell what page the client got redirected to?
回答1:
onload event
like
<iframe src="http://www.mydomain/" onLoad="alert('fire');"></iframe>
The alert will pop-up whenever the location within the iframe has changed. check it out here also
Here is a question explaining how to get current location of an iframe
回答2:
The src attribute won't change if the iframe navigates to a new page, but the location of the iframe's contentWindow will.
If you start the iframe in a page on your own domain you can use the iframes onload event to read iframe.contentWindow.location.href.
Use a try-block, and if it fails because of a cross domain call, you can return that the iframe is now in some remote site.
If it returns a value you can return the url on your site the iframe has navigated to.
回答3:
Allright, so I've been fiddeling with this script for a while now and I think I've reached a conclusion which I think is worth sharing. Cross-domain is pretty strict, and as far as I know there is no way of telling what url the xmlhttprequest object got passed on to. I did however notice a solution on another site where they suggest using a hidden iFrame (I'm referring to the link in @ayush's answer).
来源：https://stackoverflow.com/questions/4977930/is-it-possible-to-tell-if-the-src-of-an-iframe-has-changed