CSS3 100vh not constant in mobile browser

问题

I have a very odd issue... in every browser and mobile version I encountered this behavior:

all the browsers have a top menu when you load the page (showing the address bar for example) which slide up when you start scrolling the page.
100vh sometimes is calculated only on the visible part of a viewport, so when the browser bar slide up 100vh increases (in terms of pixels)
all layout re-paint and re-adjust since the dimensions have changed
a bad jumpy effect for user experience

How can avoid this problem? When I first heard of viewport-height I was excited and I thought I could use it for fixed height blocks instead of using javascript, but now I think the only way to do that is in fact javascript with some resize event...

you can see the problem at: sample site

Can anyone help me with / suggest a CSS solution?

simple test code:

/* maybe i can track the issue whe it occours... */
$(function(){
  var resized = -1;
  $(window).resize(function(){
    $('#currenth').val( $('.vhbox').eq(1).height() );
    if (++resized) $('#currenth').css('background:#00c');
  })
  .resize();
})

*{ margin:0; padding:0; }

/*
  this is the box which should keep constant the height...
  min-height to allow content to be taller than viewport if too much text
*/
.vhbox{
  min-height:100vh;
  position:relative;
}

.vhbox .t{
  display:table;
  position:relative;
  width:100%;
  height:100vh;
}

.vhbox .c{
  height:100%;
  display:table-cell;
  vertical-align:middle;
  text-align:center;
}

<div class="vhbox" style="background-color:#c00">
  <div class="t"><div class="c">
  this div height should be 100% of viewport and keep this height when scrolling page
    <br>
    <!-- this input highlight if resize event is fired -->
    <input type="text" id="currenth">
  </div></div>
</div>

<div class="vhbox" style="background-color:#0c0">
  <div class="t"><div class="c">
  this div height should be 100% of viewport and keep this height when scrolling page
  </div></div>
</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

回答1:

Unfortunately this is intentional…

This is a well know issue (at least in safari mobile), which is intentional, as it prevents other problems. Benjamin Poulain replied to a webkit bug:

This is completely intentional. It took quite a bit of work on our part to achieve this effect. :)

The base problem is this: the visible area changes dynamically as you scroll. If we update the CSS viewport height accordingly, we need to update the layout during the scroll. Not only that looks like shit, but doing that at 60 FPS is practically impossible in most pages (60 FPS is the baseline framerate on iOS).

It is hard to show you the “looks like shit” part, but imagine as you scroll, the contents moves and what you want on screen is continuously shifting.

Dynamically updating the height was not working, we had a few choices: drop viewport units on iOS, match the document size like before iOS 8, use the small view size, use the large view size.

From the data we had, using the larger view size was the best compromise. Most website using viewport units were looking great most of the time.

Nicolas Hoizey has researched this quite a bit: https://nicolas-hoizey.com/2015/02/viewport-height-is-taller-than-the-visible-part-of-the-document-in-some-mobile-browsers.html

No fix planned

At this point, there is not much you can do except refrain from using viewport height on mobile devices. Chrome changed to this as well in 2016:

https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/BK0oHURgmJ4
https://developers.google.com/web/updates/2016/12/url-bar-resizing

回答2:

You can try min-height: -webkit-fill-available; in your css instead of 100vh. It should be solved

回答3:

For many of the sites I build the client will ask for a 100vh banner and just as you have found, it results in a bad "jumpy" experience on mobile when you begin to scroll. This is how I solve the problem for a smooth consistent experience across all devices:

I first set my banner element CSS to height:100vh

Then I use jQuery to get the height in pixels of my banner element and apply an inline style using this height.

var viewportHeight = $('.banner').outerHeight();
$('.banner').css({ height: viewportHeight });

Doing this solves the issue on mobile devices as when the page loads, the banner element is set to 100vh using CSS and then jQuery overrides this by putting inline CSS on my banner element which stops it from resizing when a user begins to scroll.

However, on desktop if a user resizes their browser window my banner element won't resize because it now has a fixed height set in pixels due to the above jQuery. To address this I use Mobile Detect to add a 'mobile' class to the body of my document. And then I wrap the above jQuery in an if statement:

if ($('body').hasClass('mobile')) {
  var viewportHeight = $('.banner').outerHeight();
  $('.banner').css({ height: viewportHeight });
}

As a result, if a user is on a mobile device the class 'mobile' is present on the body of my page and the above jQuery is executed. So my banner element will only get the inline CSS applied on mobile devices meanwhile on desktop the original 100vh CSS rule remains in place.

回答4:

in my app I do it like so (typescript and nested postcss, so change the code accordingly):

const appHeight = () => {
    const doc = document.documentElement
    doc.style.setProperty('--app-height', `${window.innerHeight}px`)
}
window.addEventListener('resize', appHeight)
appHeight()

in your css:

:root {
   --app-height: 100%;
}

html,
body {
    padding: 0;
    margin: 0;
    overflow: hidden;
    width: 100vw;
    height: 100vh;

    @media not all and (hover:hover) {
        height: var(--app-height);
    }
}

it works at least on chrome mobile and ipad. What doesn't work is when you add your app to homescreen on iOS and change the orientation a few times - somehow the zoom levels mess with the innerHeight value, I might post an update if I find a solution to it.

Demo

回答5:

I came up with a React component – check it out if you use React or browse the source code if you don't, so you can adapt it to your environment.

It sets the fullscreen div's height to window.innerHeight and then updates it on window resizes.

回答6:

Look at this answer: https://css-tricks.com/the-trick-to-viewport-units-on-mobile/

// First we get the viewport height and we multiple it by 1% to get a value for a vh unit
let vh = window.innerHeight * 0.01;
// Then we set the value in the --vh custom property to the root of the document
document.documentElement.style.setProperty('--vh', `${vh}px`);

// We listen to the resize event
window.addEventListener('resize', () => {
  // We execute the same script as before
  let vh = window.innerHeight * 0.01;
  document.documentElement.style.setProperty('--vh', `${vh}px`);
});

body {
  background-color: #333;
}

.module {
  height: 100vh; /* Use vh as a fallback for browsers that do not support Custom Properties */
  height: calc(var(--vh, 1vh) * 100);
  margin: 0 auto;
  max-width: 30%;
}

.module__item {
  align-items: center;
  display: flex;
  height: 20%;
  justify-content: center;
}

.module__item:nth-child(odd) {
  background-color: #fff;
  color: #F73859;
}

.module__item:nth-child(even) {
  background-color: #F73859;
  color: #F1D08A;
}

<div class="module">
  <div class="module__item">20%</div>
  <div class="module__item">40%</div>
  <div class="module__item">60%</div>
  <div class="module__item">80%</div>
  <div class="module__item">100%</div>
</div>

回答7:

@nils explained it clearly.

What's next then?

I just went back to use relative 'classic' % (percentage) in CSS.

It's often more effort to implement something than it would be using vh, but at least, you have a pretty stable solution which works across different devices and browsers without strange UI glitches.

回答8:

I just found a web app i designed has this issue with iPhones and iPads, and found an article suggesting to solve it using media queries targeted at specific Apple devices.

I don't know whether I can share the code from that article here, but the address is this: http://webdesignerwall.com/tutorials/css-fix-for-ios-vh-unit-bug

Quoting the article: "just match the element height with the device height using media queries that targets the older versions of iPhone and iPad resolution."

They added just 6 media queries to adapt full height elements, and it should work as it is fully CSS implemented.

Edit pending: I'm unable to test it right now, but I will come back and report my results.

回答9:

The following code solved the problem (with jQuery).

var vhHeight = $("body").height();
var chromeNavbarHeight = vhHeight - window.innerHeight;
$('body').css({ height: window.innerHeight, marginTop: chromeNavbarHeight });

And the other elements use % as a unit to replace vh.

回答10:

As I am new, I can't comment on other answers.

If someone is looking for an answer to make this work (and can use javascript - as it seems to be required to make this work at the moment) this approach has worked pretty well for me and it accounts for mobile orientation change as well. I use Jquery for the example code but should be doable with vanillaJS.

-First, I use a script to detect if the device is touch or hover. Bare-bones example:

if ("ontouchstart" in document.documentElement) {
    document.body.classList.add('touch-device');

} else {
    document.body.classList.add('hover-device');
}

This adds class to the body element according to the device type (hover or touch) that can be used later for the height script.

-Next use this code to set height of the device on load and on orientation change:

if (jQuery('body').hasClass("touch-device")) {
//Loading height on touch-device
    function calcFullHeight() {
        jQuery('.hero-section').css("height", $(window).height());
    }

    (function($) {
        calcFullHeight();

        jQuery(window).on('orientationchange', function() {
            // 500ms timeout for getting the correct height after orientation change
            setTimeout(function() {
                calcFullHeight();
            }, 500);

        });
    })(jQuery);

} else {
    jQuery('.hero-section').css("height", "100vh");


}

-Timeout is set so that the device would calculate the new height correctly on orientation change. If there is no timeout, in my experience the height will not be correct. 500ms might be an overdo but has worked for me.

-100vh on hover-devices is a fallback if the browser overrides the CSS 100vh.

回答11:

The following worked for me:

html { height: 100vh; }

body {
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  width: 100vw;
}

/* this is the container you want to take the visible viewport  */
/* make sure this is top-level in body */
#your-app-container {
  height: 100%;
}

The body will take the visible viewport height and #your-app-container with height: 100% will make that container take the visible viewport height.

回答12:

Hopefully, this will be a UA-defined CSS environment variable as suggested here: https://github.com/w3c/csswg-drafts/issues/2630#issuecomment-397536046

回答13:

Because it won't be fixed, you can do something like:

# html
<body>
  <div class="content">
    <!-- Your stuff here -->
  </div>
</body>

# css
.content {
  height: 80vh;
}

For me it was the fastest and more pure solution than playing with the JavaScript which could not work on many devices and browsers.

Just use proper value of vh which fits your needs.

回答14:

Using vh on mobile devices is not going to work with 100vh, due to their design choices using the entire height of the device not including any address bars etc.

If you are looking for a layout including div heights proportionate to the true view height I use the following pure css solution:

:root {
  --devHeight: 86vh; //*This value changes
}

.div{
    height: calc(var(--devHeight)*0.10); //change multiplier to suit required height
}

You have two options for setting the viewport height, manually set the --devHeight to a height that works (but you will need to enter this value for each type of device you are coding for)

Use javascript to get the window height and then update --devheight on loading and refreshing the viewport (however this does require using javascript and is not a pure css solution)

Once you obtain your correct view height you can create multiple divs at an exact percentage of total viewport height by simply changing the multiplier in each div you assign the height to.

0.10 = 10% of view height 0.57 = 57% of view height

Hope this might help someone ;)