Background size on iOS | 易学教程

问题

I've spent the morning doing research on the following issue. I'm making a one page site, using a lot of images. I'm aware that Safari is known for its weird handling of background-attachment:fixed, but that's working fine; my problem is background-size:cover is not working in conjunction with fixed.

I have 5 pages, all of which have a height or min-height of 100%. The last page is fixed like this:

#div5 {
  height:100%;
  width:100%;
  position: relative;
  background-image: url("img/background.jpg");
  background-attachment:fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

On iOS (in both Chrome and Safari) the background image is scaled to cover the full webpage, so it's really stretched.

At the same time, page 4 has the following css:

#div4 {
  min-height:100%;
  width:100%;
  background:url(img/portfoliobg.jpg);
  overflow: auto;
  background-size: cover;
}

and this works like a charm.

So, something makes the browser behave really weirdly when combining fixed and cover. Does anyone have a solution to this?

回答1:

Use another div with position:fixed to make the background fixed.

Like this: http://codepen.io/anon/pen/OVebNg

JADE

.fixed
  .bgcover

SCSS

.fixed {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
  .bgcover {
      background-image: url('http://globe-views.com/dcim/dreams/winter/winter-04.jpg');
      background-size: cover;
    width: 100%;
    height: 100%;
  }
}

Hope this help.

回答2:

Short answer: you can’t (for now).

You can play with @media screen and (max-width: 1024px) {} but for now iPad Pro have resolution more then ordinary monitors.

I offer you to disable fixed attachment for mobiles via this way:

Main CSS file:

.parallax {
   background-attachment: fixed;
   background-size: cover;
}

Main HTML

<script type="text/javascript">
   if (navigator.userAgent.match(/(iPad|iPhone|iPod|Android|Silk)/gi)) {
      document.write("<link rel=\"stylesheet\" href=\"fixparallax.css\" />");
   }
</script>

Additional fixparallax.css

.parallax {
   background-attachment: scroll !important;
}

来源：https://stackoverflow.com/questions/21476380/background-size-on-ios

标签

html

ios

css

background-image