Have a fixed position div that needs to scroll if content overflows

问题

I have actually two issues, but lets resolve the primary issue first as I believe the other is easier to address.

I have a fixed position div on the left side of the scroll for a menu. Right side is a standard div that scrolls properly. The issue is that when the browser view-port is too small to see the entire menu.. there is no way to get it to scroll that I can find (at least not with css). I've tried using different overflows in css, but nothing makes the div scroll. The div that contains the menu is set to min-height:100% and position:fixed.. both attributes I need to keep.

The div containing the menu is inside another wrapper div that is positioned absolutely and height set to 100%.

How can I get it to scroll vertically if the content is too tall for the div?

That leads me to the other issue, that i don't want a scroll bar to display.. but I think I may already have an answer to that (only it doesn't work yet because I can't get the div to scroll to begin with).

Any solutions? Perhaps javascript is needed? (of which i know little about)

JS Fiddle Example

and the relevant code that is causing the issue (since posting the whole thing in here is waaay too long):

.fixed-content {
    min-height:100%;
    position:fixed;
    overflow-y:scroll;
    overflow-x:hidden;
}

Also tried adding height:100% as well just to see if that was an issue but it didn't work either... nor did a fixed height, such as 600px.

回答1:

The problem with using height:100% is that it will be 100% of the page instead of 100% of the window (as you would probably expect it to be). This will cause the problem that you're seeing, because the non-fixed content is long enough to include the fixed content with 100% height without requiring a scroll bar. The browser doesn't know/care that you can't actually scroll that bar down to see it

You can use fixed to accomplish what you're trying to do.

.fixed-content {
    top: 0;
    bottom:0;
    position:fixed;
    overflow-y:scroll;
    overflow-x:hidden;
}

This fork of your fiddle shows my fix: http://jsfiddle.net/strider820/84AsW/1/

回答2:

Here are both fixes.

First, regarding the fixed sidebar, you need to give it a height for it to overflow:

HTML Code:

<div id="sidebar">Menu</div>
<div id="content">Text</div>

CSS Code:

body {font:76%/150% Arial, Helvetica, sans-serif; color:#666; width:100%; height:100%;}
#sidebar {position:fixed; top:0; left:0; width:20%; height:100%; background:#EEE; overflow:auto;}
#content {width:80%; padding-left:20%;}

@media screen and (max-height:200px){
    #sidebar {color:blue; font-size:50%;}
}

Live example: http://jsfiddle.net/RWxGX/3/

It's impossible NOT to get a scroll bar if your content overflows the height of the div. That's why I've added a media query for screen height. Maybe you can adjust your styles for short screen sizes so the scroll doesn't need to appear.

Cheers, Ignacio

回答3:

Generally speaking, fixed section should be set with width, height and top, bottom properties, otherwise it won't recognise its size and position.

If the used box is direct child for body and has neighbours, then it makes sense to check z-index and top, left properties, since they could overlap each other, which might affect your mouse hover while scrolling the content.

Here is the solution for a content box (a direct child of body tag) which is commonly used along with mobile navigation.

.fixed-content {
    position: fixed;
    top: 0;
    bottom:0;

    width: 100vw; /* viewport width */
    height: 100vh; /* viewport height */
    overflow-y: scroll;
    overflow-x: hidden;
}

Hope it helps anybody. Thank you!

回答4:

Leaving an answer for anyone looking to do something similar but in a horizontal direction, like I wanted to.

Tweaking @strider820's answer like below will do the magic:

.fixed-content {        //comments showing what I replaced.
    left:0;             //top: 0;
    right:0;            //bottom:0;
    position:fixed;
    overflow-y:hidden;  //overflow-y:scroll;
    overflow-x:auto;    //overflow-x:hidden;
}

That's it. Also check this comment where @train explained using overflow:auto over overflow:scroll.

来源：https://stackoverflow.com/questions/16094785/have-a-fixed-position-div-that-needs-to-scroll-if-content-overflows

标签

javascript

css

scroll

overflow

css-position