没有固定背景高度的纯CSS视差?

时间:2016-08-01 07:49:46

标签: css css3 parallax css-transforms

我试图在没有固定背景高度的情况下获得纯CSS视差效果。这已在few places中进行了描述,但它们有一个共同的约束条件,即背景图层必须具有固定的已知高度。

由于某些动态内容,我希望在没有固定的已知背景高度的情况下使效果正常工作。

我的最小例子在这里:https://jsfiddle.net/yf8oyben/

#container {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  perspective: 1px;
  overflow-x: hidden;
  overflow-y: scroll;
}
.background {
  transform: translateZ(-1px) scale(2);
  width: 100%;
  background: lightgreen;
  height: 250px;  /* Assumes bg height */
  position: absolute;  /* Assumes bg height */
  top: calc(125px - 50vh);  /* Assumes bg height */
}
.foreground {
  background: rgba(0, 0, 255, 0.5);
  width: 100%;
  position: absolute;  /* Assumes bg height */
  top: 250px;  /* Assumes bg height */
}
<body>
  <div id='container'>
    <div id="group1">
      <div class="background">
        <div style="height: 10rem"></div>
        <center>Banner</center>
        <div style="height: 10rem"></div>
      </div>
      <div class="foreground">
        <div style="height: 10rem"></div>
        <center>Content</center>
        <div style="height: 100rem"></div>
      </div>
    </div>
  </div>
</body>

它现在有效,但假设背景为250px,在CSS中注释。是否可以删除它并仍然保留当前的效果?

1 个答案:

答案 0 :(得分:2)

您可以在不知道横幅高度的情况下实现此视差效果。你只需要放弃绝对定位并调整transform-orign*{margin:0;padding:0;} #wrap{ position:fixed; width:100%; height:100%; overflow-x:hidden; overflow-y:scroll; perspective: 1px; perspective-origin:0 0; } .bg{ background:teal; transform-origin:0 0; transform: translateZ(-1px) scale(2); } .bg img{ display:block; width:100%; height:auto; } .cont{ position:relative; background:rgba(0,0,0,0.8); color:#fff; padding:5%; } .cont *{ max-width:900px; margin:5% auto; }属性它们需要一个位于另一个之上。

以下是演示:CSS only parallax effect

<div id="wrap">
  <div class="bg">
    <img src="http://i.imgur.com/hPLqUtN.jpg" alt="" />
  </div>
  <div class="cont">
    <h1>Lorem Ipsum</h1>
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris et purus porta, porta dolor vel, pulvinar turpis. Suspendisse aliquam placerat turpis, sed ullamcorper nisl vestibulum eu. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec euismod tempor elit a pulvinar. Integer vehicula purus ipsum, id ultricies risus placerat sit amet. Cras vel ante egestas diam egestas sagittis. Mauris facilisis, dolor pulvinar tempus vestibulum, elit lectus gravida sem, sed volutpat dui dolor vel purus. Praesent nec ligula ac mi faucibus hendrerit vitae sed felis. Nullam vehicula magna vitae ultrices dapibus. Pellentesque facilisis dui a diam scelerisque pharetra. Vestibulum dapibus imperdiet molestie. Fusce fringilla facilisis metus, in iaculis lectus fermentum eget. Ut tortor quam, imperdiet sit amet nisi in, fringilla porta sapien. Aenean a enim vestibulum, bibendum dolor sed, consequat mi.</p>
    <p>Fusce faucibus nulla id iaculis sagittis. Duis ac arcu a ex elementum feugiat. Proin ut quam quis tortor vulputate semper a id nunc. Morbi rhoncus ultricies ultricies. Praesent semper id massa sed euismod. Fusce sagittis felis nec libero malesuada, in luctus enim aliquam. Aliquam sagittis, orci eget blandit vestibulum, mi dui blandit mauris, et tincidunt tellus nisi sagittis lacus. Sed dignissim, sapien vitae cursus imperdiet, augue massa tempor ex, non finibus risus metus ac enim. Mauris blandit eros nisi.</p>
    <p>Sed bibendum ante ac metus hendrerit, nec commodo tortor venenatis. Pellentesque porta eros non eros cursus, vitae commodo sapien facilisis. Praesent sit amet volutpat lacus. Nullam sed quam ac dolor blandit lacinia. Ut euismod turpis sit amet libero pulvinar, non aliquet lacus bibendum. Nullam libero massa, facilisis sed neque id, porta fringilla eros. Curabitur vestibulum nisi nec tempor tempor. Sed fermentum mauris diam, eu volutpat magna tempus et. Ut semper dapibus purus eget ullamcorper. Aenean varius rutrum purus id congue. Mauris sit amet turpis ornare, pharetra ex et, porta lorem. In hac habitasse platea dictumst.</p>
    <p>Nulla sed pellentesque nibh, eu consectetur neque. Curabitur eu risus at felis sagittis blandit. Nunc non massa non massa mattis semper. Curabitur dapibus tortor velit, id tincidunt ligula rutrum sed. Quisque feugiat consequat molestie. Curabitur lobortis neque ac porta imperdiet. Sed malesuada nibh sit amet magna commodo, sed bibendum turpis vestibulum. Suspendisse vel rutrum dolor, sed bibendum turpis. Morbi condimentum fermentum urna id venenatis.</p>
  </div>
</div>
@interface FullscreenWindow : NSWindow
@end

@implementation FullscreenWindow
-(id) init
{
    // some init code here...
    [self setLevel:NSMainMenuWindowLevel+1];
    return self;
}
@end