get the height of an element in an display: none iframe - css

Question

I try to get the height of an element that is in a iframe and that iframe is in a div with display: none. I need the height in the document in the iframe, not outside. So you don't have to think about security constrains.
Edit: Here is a small fiddle to demostrate the problem: http://jsfiddle.net/bv5JH/1/. console will log 0. And I am not able to append the div#myelement (or a copy of it) to some visible elements (so that it will be rendered and I can get the height like in the following "solution").
I found some solutions like:
var copied_elem = $("#myelement").clone()
.attr("id", false)
.css({visibility:"hidden", display:"block",
position:"absolute"});
$("body").append(copied_elem);
var height = copied_elem.height();
var width = copied_elem.width();
copied_elem.remove();
That will work if the element itself is display:none. But I dont have any displayed elements at all in the iframe, so I can't append it to a displayed element.
Any idea how to get the height anyway?

Answer 1

Since you seem to have an interaction set up between the IFRAME and your content, it should not be hard to apply this to the IFRAME itself:
position: absolute;
display: block;
top: -999999;
left: -999999;
Then you should be able to get dimensions of your element inside the IFRAME and once you got that, return that IFRAME back to its original position by resetting those styles.

Answer 2

duo to I have no enough reputation to commit.so i say here.
Change iframe's position is a good idea,yeah.
the image blow is my code which is a tab.
<div class="table census-table">
<div class="census-table-list">
<iframe src="census-baseData-iframe.php" frameborder="0" scrolling="no" width="950" 1height="590" style=""></iframe>
<iframe src="census-activeUser-iframe.php" frameborder="0" scrolling="no" width="950" 1height="590" style="display: none;"></iframe>
<iframe src="census-userKeep-iframe.php" frameborder="0" scrolling="no" width="950" 1height="590" style="display: none;"></iframe>
iframe src="census-userPay-iframe.php" frameborder="0" scrolling="no" width="950" 1height="590" style="display: none;"></iframe>
</div>
</div>