为此，您需要重新构造HTML。为了模糊背景，你必须模糊整个元素。如果你只想模糊背景，它必须是它自己的元素。

看看这支笔。

您必须使用两个不同的容器，一个用于背景图像，另一个用于内容。

在本例中，我创建了两个容器，.background-image和.content。

它们都被放置在位置:固定和左:0;右:0;。显示它们的差异来自为元素设置的不同的z-index值。

.background-image { position: fixed; left: 0; right: 0; z-index: 1; display: block; background-image: url('https://i.imgur.com/lL6tQfy.png'); width: 1200px; height: 800px; -webkit-filter: blur(5px); -moz-filter: blur(5px); -o-filter: blur(5px); -ms-filter: blur(5px); filter: blur(5px); } .content { position: fixed; left: 0; right: 0; z-index: 9999; margin-left: 20px; margin-right: 20px; } <div class="background-image"></div> <div class="content"> <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis aliquam erat in ante malesuada, facilisis semper nulla semper. Phasellus sapien neque, faucibus in malesuada quis, lacinia et libero. Sed sed turpis tellus. Etiam ac aliquam tortor, eleifend rhoncus metus. Ut turpis massa, sollicitudin sit amet molestie a, posuere sit amet nisl. Mauris tincidunt cursus posuere. Nam commodo libero quis lacus sodales, nec feugiat ante posuere. Donec pulvinar auctor commodo. Donec egestas diam ut mi adipiscing, quis lacinia mauris condimentum. Quisque quis odio venenatis, venenatis nisi a, vehicula ipsum. Etiam at nisl eu felis vulputate porta.</p> <p>Fusce ut placerat eros. Aliquam consequat in augue sed convallis. Donec orci urna, tincidunt vel dui at, elementum semper dolor. Donec tincidunt risus sed magna dictum, quis luctus metus volutpat. Donec accumsan et nunc vulputate accumsan. Vestibulum tempor, erat in mattis fringilla, elit urna ornare nunc, vel pretium elit sem quis orci. Vivamus condimentum dictum tempor. Nam at est ante. Sed lobortis et lorem in sagittis. In suscipit in est et vehicula.</p> </div>

为Lorem Ipsum的文本道歉。

更新

感谢Matthew Wilcoxson在https://codepen.io/akademy/pen/FlkzB之前使用.content::提供了更好的实现

在CSS的.content选项卡中将其更改为position:absolute。否则，渲染的页面将不可滚动。

pen

取消了对额外元素的需求，同时使内容适合文档流，而不是像其他解决方案那样固定/绝对。

通过使用

.content { /* this is needed or the background will be offset by a few pixels at the top */ overflow: auto; position: relative; } .content::before { content: ""; position: fixed; left: 0; right: 0; z-index: -1; display: block; background-image: url('https://i.imgur.com/lL6tQfy.png'); background-size:cover; width: 100%; height: 100%; -webkit-filter: blur(5px); -moz-filter: blur(5px); -o-filter: blur(5px); -ms-filter: blur(5px); filter: blur(5px); } <div class="content"> Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. </div>

编辑如果你想删除边缘的白色边框，使用宽度和高度为110%，左侧和顶部为-5%。这将放大你的背景-但不应该有纯色从边缘流出。感谢Chad Fawcett的建议。

.content { /* this is needed or the background will be offset by a few pixels at the top */ overflow: auto; position: relative; } .content::before { content: ""; position: fixed; top: -5%; left: -5%; right: -5%; z-index: -1; display: block; background-image: url('https://i.imgur.com/lL6tQfy.png'); background-size:cover; width: 110%; height: 110%; -webkit-filter: blur(5px); -moz-filter: blur(5px); -o-filter: blur(5px); -ms-filter: blur(5px); filter: blur(5px); } <div class="content"> Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. </div>

请检查以下代码:-

.backgroundImageCVR{ position:relative; padding:15px; } .background-image{ position:absolute; left:0; right:0; top:0; bottom:0; background:url('https://i.imgur.com/5SZI6qZ.jpeg'); background-size:cover; z-index:1; -webkit-filter: blur(10px); -moz-filter: blur(10px); -o-filter: blur(10px); -ms-filter: blur(10px); filter: blur(10px); } .content{ position:relative; z-index:2; color:#fff; } <div class="backgroundImageCVR"> <div class="background-image"></div> <div class="content"> <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis aliquam erat in ante malesuada, facilisis semper nulla semper. Phasellus sapien neque, faucibus in malesuada quis, lacinia et libero. Sed sed turpis tellus. Etiam ac aliquam tortor, eleifend rhoncus metus. Ut turpis massa, sollicitudin sit amet molestie a, posuere sit amet nisl. Mauris tincidunt cursus posuere. Nam commodo libero quis lacus sodales, nec feugiat ante posuere. Donec pulvinar auctor commodo. Donec egestas diam ut mi adipiscing, quis lacinia mauris condimentum. Quisque quis odio venenatis, venenatis nisi a, vehicula ipsum. Etiam at nisl eu felis vulputate porta.</p> <p>Fusce ut placerat eros. Aliquam consequat in augue sed convallis. Donec orci urna, tincidunt vel dui at, elementum semper dolor. Donec tincidunt risus sed magna dictum, quis luctus metus volutpat. Donec accumsan et nunc vulputate accumsan. Vestibulum tempor, erat in mattis fringilla, elit urna ornare nunc, vel pretium elit sem quis orci. Vivamus condimentum dictum tempor. Nam at est ante. Sed lobortis et lorem in sagittis. In suscipit in est et vehicula.</p> </div> </div>

虽然所有提到的解决方案都非常聪明，但当我尝试它们时，它们似乎都有一些小问题或与页面上的其他元素产生潜在的连锁影响。

最后，为了节省时间，我只是回到了我以前的解决方案:我使用Paint。选择效果，高斯模糊，半径5到10像素，保存为页面图像。: -)

HTML:

<body class="mainbody">
</body

CSS:

body.mainbody
{
    background: url('../images/myphoto.blurred.png');
    -moz-background-size: cover;
    -webkit-background-size: cover;
    background-size: cover;
    background-position: top center !important;
    background-repeat: no-repeat !important;
    background-attachment: fixed;
}

编辑:

我终于让它工作了，但解决方案绝不简单!在这里看到的:

过滤器:模糊(1 px);不能在firefox, IE和opera中工作

正如在其他答案中所述，这可以通过以下方式实现:

作为背景的模糊图像的副本。 可以过滤的伪元素，然后将其定位在内容后面。

你也可以使用backdrop-filter

有一个受支持的属性叫做backdrop-filter，目前是 支持Chrome, Firefox, Edge, Safari和iOS Safari(查看caniuse.com统计数据)。

来自Mozilla devdocs:

backdrop-filter属性提供了一些效果，比如对元素后面的区域进行模糊或颜色移动，然后通过调整元素的透明度/不透明度就可以看到元素。

查看caniuse.com了解使用统计数据。

你会这样使用它。 如果你不想让里面的内容被模糊化，使用实用工具类.u-non- ambiguous

.background-filter::after { -webkit-backdrop-filter: blur(5px); /* Use for Safari 9+, Edge 17+ (not a mistake) and iOS Safari 9.2+ */ backdrop-filter: blur(5px); /* Supported in Chrome 76 */ content: ""; display: block; position: absolute; width: 100%; height: 100%; top: 0; } .background-filter { position: relative; } .background { background-image: url('https://upload.wikimedia.org/wikipedia/en/6/62/Kermit_the_Frog.jpg'); width: 200px; height: 200px; } /* Use for content that should not be blurred */ .u-non-blurred { position: relative; z-index: 1; } <div class="background background-filter"></div> <div class="background background-filter"> <h1 class="u-non-blurred">Kermit D. Frog</h1> </div>

如果你想要内容是可滚动的，设置内容的位置为绝对:

content {
   position: absolute;
   ...
}

我不知道这是不是只适合我，但如果不是，这就是解决办法!

此外，由于背景是固定的，这意味着你有一个“视差”效果!所以现在，这个人不仅教你如何制作一个模糊的背景，而且它也是一个视差背景效果!

这个答案是为材料设计水平卡片布局动态高度和图像。

为了防止由于卡片的动态高度而导致图像失真，您可以使用带有模糊的背景占位符图像来调整高度的变化。

解释

The card is contained in a <div> with class wrapper, which is a flexbox. The card is made up of two elements, an image which is also a link, and content. The link <a>, class link, is positioned relative. The link consists of two sub-elements, a placeholder <div> class blur and an <img> class pic which is the clear image. Both are positioned absolute and have width: 100%, but class pic has a higher stack order, i.e., z-index: 2, which places it above the placeholder. The background image for the blurred placeholder is set via inline style in the HTML.

Code

.wrapper { display: flex; width: 100%; border: 1px solid rgba(0, 0, 0, 0.16); box-shadow: 0 1px 1px rgba(0, 0, 0, 0.16), 0 1px 1px rgba(0, 0, 0, 0.23); background-color: #fff; margin: 1rem auto; height: auto; } .wrapper:hover { box-shadow: 0 3px 6px rgba(0, 0, 0, 0.16), 0 3px 6px rgba(0, 0, 0, 0.23); } .link { display: block; width: 200px; height: auto; overflow: hidden; position: relative; border-right: 2px solid #ddd; } .blur { position: absolute; top: 0; left: 0; right: 0; bottom: 0; margin: auto; width: 100%; height: 100%; filter: blur(5px); -webkit-filter: blur(5px); -moz-filter: blur(5px); -o-filter: blur(5px); -ms-filter: blur(5px); } .pic { width: calc(100% - 20px); max-width: 100%; height: auto; margin: auto; position: absolute; top: 0; left: 0; right: 0; bottom: 0; z-index: 2; } .pic:hover { transition: all 0.2s ease-out; transform: scale(1.1); text-decoration: none; border: none; } .content { display: flex; flex-direction: column; width: 100%; max-width: 100%; padding: 20px; overflow-x: hidden; } .text { margin: 0; } <div class="wrapper"> <a href="#" class="link"> <div class="blur" style="background: url('https://i.imgur.com/5SZI6qZ.jpeg') 50% 50% / cover;"></div> <img src="https://i.imgur.com/5SZI6qZ.jpeg" alt="Title" class="pic" /> </a> <div class="content"> <p class="text">Agendum dicendo memores du gi ad. Perciperem occasionem ei ac im ac designabam. Ista rom sibi vul apud tam. Notaverim to extendere expendere concilium ab. Aliae cogor tales fas modus parum sap nullo. Voluntate ingressus infirmari ex mentemque ac manifeste eo. Ac gnum ei utor sive se. Nec curant contra seriem amisit res gaudet adsunt. </p> </div> </div>

下面是一个简单的解决方案，适用于现代浏览器，使用纯CSS和一个'before'伪元素，就像Matthew Wilcoxson的解决方案一样。

为了避免在JavaScript中需要访问伪元素来更改图像和其他属性，只需使用inherit作为值，并通过父元素(这里是body)访问它们。

body::before {
    content: ""; /* Important */
    z-index: -1; /* Important */
    position: inherit;
    left: inherit;
    top: inherit;
    width: inherit;
    height: inherit;
    background-image: inherit;
    background-size: cover;
    filter: blur(8px);
}

body {
  background-image: url("xyz.jpg");
  background-size: 0 0;  /* Image should not be drawn here */
  width: 100%;
  height: 100%;
  position: fixed; /* Or absolute for scrollable backgrounds */
}

div { background: inherit; width: 250px; height: 350px; position: absolute; overflow: hidden; /* Adding overflow hidden */ } div:before { content: ‘’; width: 300px; height: 400px; background: inherit; position: absolute; left: -25px; /* Giving minus -25px left position */ right: 0; top: -25px; /* Giving minus -25px top position */ bottom: 0; box-shadow: inset 0 0 0 200px rgba(255, 255, 255, 0.3); filter: blur(10px); }

当然，这不是css解决方案，但你可以使用CDN质子过滤器:

body {
    background: url('https://i0.wp.com/IMAGEURL?w=600&filter=blurgaussian&smooth=1');
}

它来自https://developer.wordpress.com/docs/photon/api/#filter

你所需要的只是“filter”:

blur(«WhatEverYouWantInPixels»);"

body { color: #fff; font-family: Helvetica, Arial, sans-serif; } #background { background-image: url('https://cdn2.geckoandfly.com/wp-content/uploads/2018/03/ios-11-3840x2160-4k-5k-beach-ocean-13655.jpg'); background-repeat: no-repeat; background-size: cover; width: 100vw; height: 100vh; overflow: hidden; position: absolute; top: 0; left: 0; z-index: -1; /* START */ /* START */ /* START */ /* START */ /* You can adjust the blur-radius as you'd like */ filter: blur(3px); } <div id="background"></div> <p id="randomContent">Lorem Ipsum</p>

我没有写这个，但是我注意到使用CSS SASS编译器有一个部分支持的后台过滤器的polyfill，所以如果你有一个编译管道，它可以很好地实现(它也使用TypeScript):

https://codepen.io/mixal_bl4/pen/EwPMWo

现在，通过使用CSS GRID，这变得更加简单和灵活。你只需要将模糊的背景(imgbg)与文本(h2)重叠即可。

<div class="container">
 <div class="imgbg"></div>
 <h2>
  Lorem ipsum dolor sit amet consectetur, adipisicing elit. Facilis enim
  aut rerum mollitia quas voluptas delectus facere magni cum unde?:)
 </h2>
</div>

还有css:

.container {
        display: grid;
        width: 30em;
      }

.imgbg {
        background: url(bg3.jpg) no-repeat center;
        background-size: cover;
        grid-column: 1/-1;
        grid-row: 1/-1;
        filter: blur(4px);
      }


     .container h2 {
        text-transform: uppercase;
        grid-column: 1/-1;
        grid-row: 1/-1;
        z-index: 2;
      }

$fondo: url(/grid/assets/img/backimage.png);    
{ padding: 0; margin: 0; } 
body { 
    ::before{
        content:"" ; height: 1008px; width: 100%; display: flex; position: absolute; 
        background-image: $fondo ; background-repeat: no-repeat ; background-position: 
        center; background-size: cover; filter: blur(1.6rem);
    }
}

不使用伪类from

身体{ 背景:# cecece; font-family: "Scope One"， serif; 字体大小:12 px; 颜色:黑色; 保证金:0汽车; 高度:100%; 宽度:100%; 背景图片: 线性梯度(到底部，rgba(0,0,0,0.8)， rgba(0,0,0, 0.81))， url (https://i.imgur.com/2rRMQh7.jpg); -webkit-background-size:封面; -moz-background-size:封面; -o-background-size:封面; background-size:封面; ｝ 身体身体< > < / >

你可以在你想要应用过滤器的图像上创建一个div，并使用backdrop-filter到它的CSS类。 看看这个链接

CSS网格对我来说更容易理解。：）

html, body { width: 100%; height: 100%; } .container { width: 100%; height: 100%; display: grid; grid-template-columns: 1fr 6fr 1fr; grid-template-rows: 1fr 6fr 1fr; grid-template-areas: '. . .' '. content .' '. . .'; justify-content: center; align-items: center; } .backbround { width: 100%; height: 100%; grid-area: 1/1/5/5; background-image: url(https://i.imgur.com/aUhpEz3.jpg); filter: blur(5px); background-position: center; background-repeat: no-repeat; background-size: cover; } .content { height: 200px; position: relative; grid-area: content; display: flex; justify-content: center; align-items: center; color: white; } <div class="container"> <div class="backbround"></div> <div class="content"><h1>Hello World</h1></div> </div>

成功应用背景图像的步骤

确保使用link标签正确链接了HTML和CSS <link rel="stylesheet" ref="yourcssdocument.css"> 我不知道相对目录和子目录，所以我不能评论它 对我来说，最好的方法是在css中使用URL链接

#yourcssdoc .image {
   background-image: url("paste your link here with the quotations")
}

<!-- Q:Create the blur on parenttal div without effecting the child div -->

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    *{
        margin: 0; padding: 0; box-sizing: border-box;
        font-size: 30px;
    }
    .parent{
background-image:url(hobby.jpg) ;
height: 100vh;
width: 100vw;
background-repeat: no-repeat;
background-size: cover;
background-position: center;

display: flex;
justify-content: center;
align-items: center;
    }
    .child{
   
    height: 90vh;
    width: 90vw;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(0, 0, 0, 0.418);
  justify-content: center;
  align-items: center;
    display: flex;
    
 
    }
  .text{
    
      height: 300px;
      width: 300px;
      border-radius: 500px;
      background-image: url(50cf380e5c78eb174faa8e6ac2cb654a.jpg);
      background-size: cover;
      background-position: center;
      

  }
    
    
</style>
<body>
    <div class="parent">
        <div class="child">
       <div class="text"></div>
        </div>
    </div>
</body>
</html>

规范引入了一个新的filter()函数，你可以像下面这样使用背景图像:

background: filter(url("whatever.jpg"), blur(5px));

<filter()>函数有两个参数。第一个参数是<image>。第二个是为CSS filter属性指定的筛选器函数列表。该函数接受参数并应用筛选规则，返回一个处理图像。

但是浏览器不支持这个:https://caniuse.com/css-filter-function。目前只能在Safari上进行测试。