自举模式删除滚动条

This is a feature, class modal-open gets added to the HTML body when you show the modal, and removed when you hide it.

This makes the scrollbar disappear since the bootstrap css says

.modal-open {
overflow: hidden;
}

You can override this by specifying

.modal-open {
overflow: scroll;
}

in your own css.

Better if you will create your own css file to customize a certain part of your bootsrap.

Do not Alter the css file of bootstrap because it will change everything in your bootstrap once you use it in other parts of your page.

If your page is somewhat long, it will automatically provide a scroll bar. And when the modal opened, it will hide the scroll bar because that's what bootstrap do as a default.

To avoid hiding it when modal is opened, just override it by putting the css code (below) on your own css file.

.modal-open {
overflow: scroll;
}

just a vice versa...

.modal-open {
overflow: hidden;
}

I used

.modal-open {
overflow-y: scroll;
}

In this case you avoids to display the horizontal scroll bar

Thank God I came accross this post! I was pulling my hair out trying to figure how to get my scrollbars back when closing the window using my own close link. I tried the suggestions for CSS but it just wasnt working properly. After reading

class modal-open gets added to the HTML body when you show the modal, and removed when you hide it. -- @flup

I came up with a solution using jquery, so incase anyone else has the same issue and the above suggestions dont work --

<script>
jQuery(document).ready(function () {
jQuery('.closeit').click(function () {
jQuery('body').removeClass('modal-open');
});
});
</script>

I think that inherit is better than scroll because when you open modal, it will always open with scroll, but when you don't have any scrolls you will get the same problem. So I just do this:

.modal-open {
overflow: inherit;
}

I was just playing with this 'feature' of Bootstrap modals. Seems the .modal class has overflow-y:auto; So the modal wrapper gets his own scrollbar when the modal itself becomes to high.

If you always want a scrollbar (designers often do) First set the body

body {
overflow-y:scroll;
}

Then handle .modal-open

.modal-open .modal {
overflow-y:scroll; /* Force a navbar on .modal */
}


.modal-open .topnavbar-wrapper {
padding-right:17px; /* Noticed that right aligned navbar content got overlapped by the .modal scrollbar */
}

Leave scrollbar disabling on body untouched in this case

All other answers on this page kept making my content jump.

Heads up!

Allthough this solution worked for me all the time, yesterday I had a problem using this fix when the modal is draggable and to large to fit the screen (vertically). It might have something to do with position:sticky elements I added?

Its better to use overflow-y:scroll and remove padding from body, bootstrap modal added padding to page body.

.modal-open {
overflow:hidden;
overflow-y:scroll;
padding-right:0 !important;
}

IE browser Compatible: IE browser doing same thing by default.

the bootstrap modal adds a padding once it opens so you can try this code in your own css

.modal-open {
padding: 0 !important;
}

Additionally, if modal popup needs to scroll with content inside and the parent needs to remain still, add the following to your Custom.css (overriding css)

.modal-body {
max-height: calc(100vh - 210px);
overflow-y: auto;
}
.modal-open {
overflow: hidden;
overflow-y: scroll;
padding-right: 0 !important;
}

This is probably caused that 1st modal (when closed) remove modal-open class from body element and second one wont add it back when trigger modal-open.

In this case I would use event to check if modal has been closed/hidden fully and open another

let modal1 = $('.modal1);
let modal2 = $('.modal2);
$modal1.on('hidden.bs.modal', function (e) {
$modal2.modal('show');
});

This will wait till 1st modal is closed to make sure modal-open is removed from body and re-added it when open.

I just had this problem myself, and finding this question quickly helped me understand what was causing the behaviour. So thanks.

However, I find these CSS workarounds a bit inelegant. Unless, that is, you specifically want to keep the scrollbars (although I can't think of a reason for that).

Essentially Bootstrap is applying padding-right to certain elements to compensate for removing the scrollbar.

Therefore, all you need to do is to put an extra wrapper with zero padding-right around your problematic element (and move the class that's being targeted up to it).

i.e. change from this...

<div class="fixed-top p-1 bg-dark">
...this content will move as padding will be modified...
</div>

... to this...

<div class="fixed-top p-0 bg-dark">
<div class="p-1">
...this content won't move...
</div>
</div>

The only answer that worked for me is the following:

.modal-open {
padding-right: 0 !important;
}
html {
overflow-y: scroll !important;
}

In my case, bootstrap adds margin-left: -17px to my sidebar element by opening the modal. My solution on this, is to add m-0 class to sidebar.

Just so PrimeNg users can get help here, PrimeNg does the same thing:

.p-overflow-hidden {
overflow: hidden;
}

In the case of PrimeNg though, it can be disabled by disabling the modal property when opening the DynamicDialog; if that's appropriate for your use-case.

Otherwise, it requires the same fix as Bootstrap.