问题
Im trying to set an automatic height a div that contains 2 child elements, positioned fixed and absolutely respecitvely.
I want my parent container to have an auto height but I know this is hard as the child elements are taken out of the page structure with their positions.
I have tried setting a height to my parent div that works, but with my layout being responsive, when its scaled down to mobile, the height remains the same where as the content within becomes stacked and so the height needs to increase with its children.
Not sure if this makes sense, I dont have my actual code on me atm but ive made a fiddle trying to explain...
http://jsfiddle.net/dPCky/
回答1:
The parent div can not use height:auto when its children are positioned absolute / fixed.
You would need to use JavaScript to achieve this.
An example in jQuery:
var biggestHeight = 0;
// Loop through elements children to find & set the biggest height
$(".container *").each(function(){
// If this elements height is bigger than the biggestHeight
if ($(this).height() > biggestHeight ) {
// Set the biggestHeight to this Height
biggestHeight = $(this).height();
}
});
// Set the container height
$(".container").height(biggestHeight);
Working example http://jsfiddle.net/blowsie/dPCky/1/
回答2:
http://jsfiddle.net/dPCky/32/ - A similar effect using float:left;
http://jsfiddle.net/dPCky/40/ - An even closer result to your desired effect.
If you're willing to change your html, then you could do what I have done above.
I learned positioning from the following tutorials which I would highly recommend to anyone who wants to become a positioning pro in html/css:
http://www.barelyfitz.com/screencast/html-training/css/positioning/
I would generally avoid using javascript where possible when doing something that could potentially have a css or html level fix, if you're willing to adjust your html.
回答3:
If you don't want to use JavaScript, you could refer this answer https://stackoverflow.com/a/33788333/1272106.
Short description: duplicate one element and set visibility to hide to expand the parent.
回答4:
A little late to the party, but this may help someone as this is how I resolved the issue recently without JS - IF the children maintain their aspect ratio as they shrink for mobile devices. My example relates to making a jQuery.cycle slideshow responsive, for context. Unsure if this is what you're trying to achieve above, but it involved absolutely positioned children within a container which has 100% page width on mobile and explicit dimensions on larger screens.
You can set the parent's height to use viewport width units (vw), so the height adapts relative to the device's width. Support is broad enough these days that most mobile devices will use these units correctly, bugs and partial support don't relate to vw (but rather, to vmin and vmax in IE). Only Opera Mini is in the dark.
Without knowing what the children are doing between responsive points in this example (the jsfiddle has explicit heights set), let's assume the height of the children scales down predictably relative to the device width, which allows you to fairly accurately assume the height based on aspect ratio.
.container{ height: 75vw; }
http://caniuse.com/#feat=viewport-units
Do note known issue #7 on caniuse if you're going for 100vw as a width measure, but here we're playing with height!
回答5:
Enjoy this auto height for container that adapts to any device and viewport resize or rotation.
It has been tested with float, inline-block, absolute, margins and padding set to the childs.
<div class="autoheight" style="background: blue">
<div style="position: absolute; width: 33.3%; background: red">
Only
<div style="background: green">
First level elements are measured as expected
</div>
</div>
<div style="float:left; width: 33.3%; background: red">
One Two Three Four Five Six Seven Eight Night Ten
</div>
<div style="float:left; width: 33.3%; background: red">
One Two Three Four Five Six
</div>
</div>
<script>
function processAutoheight()
{
var maxHeight = 0;
// This will check first level children ONLY as intended.
$(".autoheight > *").each(function(){
height = $(this).outerHeight(true); // outerHeight will add padding and margin to height total
if (height > maxHeight ) {
maxHeight = height;
}
});
$(".autoheight").height(maxHeight);
}
// Recalculate under any condition that the viewport dimension has changed
$(document).ready(function() {
$(window).resize(function() { processAutoheight(); });
// BOTH were required to work on any device "document" and "window".
// I don't know if newer jQuery versions fixed this issue for any device.
$(document).resize(function() { processAutoheight(); });
// First processing when document is ready
processAutoheight();
});
</script>
回答6:
The right way... simple. No Javascript.
<div class="container">
<div class="faq-cards">
<div class="faq-cards__card">Im A Card</div>
<div class="faq-cards__card">Im A Card</div>
<div class="faq-cards__card">Im A Card</div>
<div class="faq-cards__card">Im A Card</div>
<div class="faq-cards__card">Im A Card</div>
<div class="faq-cards__card">Im A Card</div>
<div class="faq-cards__card">Im A Card</div>
</div>
</div>
.container {
height: auto;
width: 1280px;
margin: auto;
background: #CCC;
}
.faq-cards {
display: flex;
flex-wrap: wrap;
justify-content: center;
position: relative;
bottom: 40px;
height: auto;
}
.faq-cards__card {
position: relative;
margin: 10px;
padding: 10px;
width: 225px;
height: 100px;
background: beige;
text-align: center;
}
https://codepen.io/GerdSuhr/pen/jgqOJp
回答7:
Related to @Blowsie's answer:
/**
* Sets the height of a container to its maximum height of its children. This
* method is required in case
*
* @param selector jQuery selector
*/
function setHeightByChildrenHeight(selector)
{
$(selector).each(function()
{
var height = 0;
$(this).children("*").each(function()
{
height = Math.max(height, $(this).height());
});
$(this).height(height);
});
};
回答8:
An easier way is:
$(".container").height($(document).height());
来源：https://stackoverflow.com/questions/9061520/auto-height-on-parent-container-with-absolute-fixed-children