禁用 Bootstrap 的坍塌打开/关闭动画

Bootstrap 2 CSS solution:

.collapse {  transition: height 0.01s; }

NB: setting transition: none disables the collapse functionnality.

Bootstrap 4 solution:

.collapsing {
transition: none !important;
}

For Bootstrap 3 and 4 it's

.collapsing {
-webkit-transition: none;
transition: none;
display: none;
}

If you find the 1px jump before expanding and after collapsing when using the CSS solution a bit annoying, here's a simple JavaScript solution for Bootstrap 3...

Just add this somewhere in your code:

$(document).ready(
$('.collapse').on('show.bs.collapse hide.bs.collapse', function(e) {
e.preventDefault();
}),
$('[data-toggle="collapse"]').on('click', function(e) {
e.preventDefault();
$($(this).data('target')).toggleClass('in');
})
);

Maybe not a direct answer to the question, but a recent addition to the official documentation describes how jQuery can be used to disable transitions entirely just by:

$.support.transition = false

Setting the .collapsing CSS transitions to none as mentioned in the accepted answer removed the animation. But this — in Firefox and Chromium for me — creates an unwanted visual issue on collapse of the navbar.

For instance, visit the Bootstrap navbar example and add the CSS from the accepted answer:

.collapsing {
-webkit-transition: none;
transition: none;
}

What I currently see is when the navbar collapses, the bottom border of the navbar momentarily becomes two pixels instead of one, then disconcertingly jumps back to one. Using jQuery, this artifact doesn't appear.