定位元件垂直固定，绝对水平固定

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最佳答案

Position Fixed Element Horizontally Based Off Another Element

(Disclaimer Note: The solution offered here is not technically "absolute horizontally" as the question title stated, but did achieve what the OP originally wanted, the fixed position element to be 'X' distance from the right edge of another but fixed in its vertical scroll.)

I love these types of css challenges. As a proof of concept, yes, you can get what you desire. You may have to tweak some things for your needs, but here is some sample html and css that passed FireFox, IE8 and IE7 (IE6, of course, does not have position: fixed).

HTML:

<body>
<div class="inflow">
<div class="positioner"><!-- may not be needed: see notes below-->
<div class="fixed"></div>
</div>
</div>
</body>

CSS (borders and all dimensions for demonstration):

div.inflow {
width: 200px;
height: 1000px;
border: 1px solid blue;
float: right;
position: relative;
margin-right: 100px;
}
div.positioner {position: absolute; right: 0;} /*may not be needed: see below*/
div.fixed {
width: 80px;
border: 1px solid red;
height: 100px;
position: fixed;
top: 60px;
margin-left: 15px;
}

The key is to not set the left or right at all for the horizontal on the div.fixed but use the two wrapper divs to set the horizontal position. The div.positioner is not needed if the div.inflow is a fixed width, as the left margin of the div.fixed can be set to known width of the container. However, if you desire than container to have a percentage width, then you will need the div.positioner to push the div.fixed to the right side of the div.inflow first.

Edit: As an interesting side note, when I set overflow: hidden (should one need to do that) on the div.inflow had no effect on the fixed position div being outside the other's boundaries. Apparently the fixed position is enough to take it out of the containing div's context for overflow.

小开

I arrived here looking for a solution to a similar problem, which was to have a footer bar that spans the width of the window and sits below the (variable height and width) content. In other words, make it appear that the footer is "fixed" with respect to its horizontal position, but retains its normal postion in the document flow with respect to its vertical position. In my case, I had the footer text right-aligned, so it worked for me to dynamically adjust the width of the footer. Here is what I came up with:

HTML

<div id="footer-outer">
<div id="footer">
Footer text.
</div><!-- end footer -->
</div><!-- end footer-outer -->

CSS

#footer-outer
{
width: 100%;
}
#footer
{
text-align: right;
background-color: blue;
/* various style attributes, not important for the example */
}

CoffeeScript / JavaScript

(Using prototype.js).

class Footer
document.observe 'dom:loaded', ->
Footer.width = $('footer-outer').getDimensions().width
Event.observe window, 'scroll', ->
x = document.viewport.getScrollOffsets().left
$('footer-outer').setStyle( {'width': (Footer.width + x) + "px"} )

which compiles into:

Footer = (function() {


function Footer() {}


return Footer;


})();


document.observe('dom:loaded', function() {
return Footer.width = $('footer-outer').getDimensions().width;
});


Event.observe(window, 'scroll', function() {
var x;
x = document.viewport.getScrollOffsets().left;
return $('footer-outer').setStyle({
'width': (Footer.width + x) + "px"
});
});

This works nicely in FireFox, and pretty well in Chrome (it's a little jittery); I haven't tried other browsers.

I also wanted any spare space below the footer to be a different colour, so I added this footer-stretch div:

HTML

...
</div><!-- end footer -->
<div id="footer-stretch"></div>
</div><!-- end footer-outer -->

CSS

#footer-outer
{
height: 100%;
}
#footer-stretch
{
height: 100%;
background-color: #2A2A2A;
}

Note that for the #footer-stretch div to work, all the parent elements up to the body element (and possibly the html element - not sure) must have a fixed height (in this case, height = 100%).

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After much digging (including this post) I couldn't find a solution that I liked. The Accepted Answer here doesn't do what the OP's title read, and the best solutions I could find admittedly resulted in jumpy elements. Then, it hit me: Have the element be "fixed", detect when a horizontal scroll occurs, and switch it to be absolutely positioned. Here is the resulting code:

View it as a Code Pen.

HTML

  <div class="blue">
<div class="red">
</div>
</div>

CSS

/* Styling */
.blue, .red {
border-style: dashed;
border-width: 2px;
padding: 2px;
margin-bottom: 2px;
}


/* This will be out "vertical-fixed" element */
.red {
border-color: red;
height: 120px;
position: fixed;
width: 500px;
}


/* Container so we can see when we scroll */
.blue {
border-color: blue;
width: 50%;
display: inline-block;
height: 800px;
}

JavaScript

$(function () {
var $document = $(document),
left = 0,
scrollTimer = 0;


// Detect horizontal scroll start and stop.
$document.on("scroll", function () {
var docLeft = $document.scrollLeft();
if(left !== docLeft) {
var self = this, args = arguments;
if(!scrollTimer) {
// We've not yet (re)started the timer: It's the beginning of scrolling.
startHScroll.apply(self, args);
}
window.clearTimeout(scrollTimer);
scrollTimer = window.setTimeout(function () {
scrollTimer = 0;
// Our timer was never stopped: We've finished scrolling.
stopHScroll.apply(self, args);
}, 100);
left = docLeft;
}
});


// Horizontal scroll started - Make div's absolutely positioned.
function startHScroll () {
console.log("Scroll Start");
$(".red")
// Clear out any left-positioning set by stopHScroll.
.css("left","")
.each(function () {
var $this = $(this),
pos = $this.offset();
// Preserve our current vertical position...
$this.css("top", pos.top)
})
// ...before making it absolutely positioned.
.css("position", "absolute");
}


// Horizontal scroll stopped - Make div's float again.
function stopHScroll () {
var leftScroll = $(window).scrollLeft();
console.log("Scroll Stop");
$(".red")
// Clear out any top-positioning set by startHScroll.
.css("top","")
.each(function () {
var $this = $(this),
pos = $this.position();
// Preserve our current horizontal position, munus the scroll position...
$this.css("left", pos.left-leftScroll);
})
// ...before making it fixed positioned.
.css("position", "fixed");
}
});