What is the simplest jQuery way to have a 'position:fixed' (always at top) div?

倾然丶 夕夏残阳落幕 提交于 2019-11-26 23:51:06

Using this HTML:

<div id="myElement" style="position: absolute">This stays at the top</div>

This is the javascript you want to use. It attaches an event to the window's scroll and moves the element down as far as you've scrolled.

$(window).scroll(function() {
    $('#myElement').css('top', $(this).scrollTop() + "px");
});

As pointed out in the comments below, it's not recommended to attach events to the scroll event - as the user scrolls, it fires A LOT, and can cause performance issues. Consider using it with Ben Alman's debounce/throttle plugin to reduce overhead.

For those browsers that do support "position: fixed" you can simply use javascript (jQuery) to change the position to "fixed" when scrolling. This eliminates the jumpiness when scrolling with the $(window).scroll(function()) solutions listed here.

Ben Nadel demonstrates this in his tutorial: Creating A Sometimes-Fixed-Position Element With jQuery

Timothy Khouri

Beautiful! Your solution was 99%... instead of "this.scrollY", I used "$(window).scrollTop()". What's even better is that this solution only requires the jQuery1.2.6 library (no additional libraries needed).

The reason I wanted that version in particular is because that's what ships with MVC currently.

Here's the code:

$(document).ready(function() {
    $("#topBar").css("position", "absolute");
});

$(window).scroll(function() {
    $("#topBar").css("top", $(window).scrollTop() + "px");
});

HTML/CSS Approach

If you are looking for an option that does not require much JavaScript (and and all the problems that come with it, such as rapid scroll event calls), it is possible to gain the same behavior by adding a wrapper <div> and a couple of styles. I noticed much smoother scrolling (no elements lagging behind) when I used the following approach:

JS Fiddle

HTML

<div id="wrapper">
  <div id="fixed">
    [Fixed Content]
  </div><!-- /fixed -->
  <div id="scroller">
    [Scrolling Content]
  </div><!-- /scroller -->
</div><!-- /wrapper -->

CSS

#wrapper { position: relative; }
#fixed { position: fixed; top: 0; right: 0; }
#scroller { height: 100px; overflow: auto; }

JS

//Compensate for the scrollbar (otherwise #fixed will be positioned over it).
$(function() {
  //Determine the difference in widths between
  //the wrapper and the scroller. This value is
  //the width of the scroll bar (if any).
  var offset = $('#wrapper').width() - $('#scroller').get(0).clientWidth;

  //Set the right offset
  $('#fixed').css('right', offset + 'px');​
});

Of course, this approach could be modified for scrolling regions that gain/lose content during runtime (which would result in addition/removal of scrollbars).

For anyone still looking for an easy solution in IE 6. I created a plugin that handles the IE 6 position: fixed problem and is very easy to use: http://www.fixedie.com/

I wrote it in an attempt to mimic the simplicity of belatedpng, where the only changes necessary are adding the script and invoking it.

In a project, my client would like a floating box in another div, so I use margin-top CSS property rather than top in order to my floating box stay in its parent.

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