父元素background-filter不适用于其子元素 [英] Parent element backdrop-filter does not apply for its child
本文介绍了父元素background-filter不适用于其子元素的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
请参考以下代码段.我想知道如何使背景滤镜应用于下拉菜单 ul ?
Please refer to the following snippet. I'm wondering how to make the backdrop-filter apply to the drop down menu ul?
nav {
position: fixed;
top: 0;
left: 0;
right: 0;
height: 50px;
background: hsla(0, 0%, 100%, 80%);
border-bottom: 1px solid hsla(0, 0%, 0%, 10%);
-webkit-backdrop-filter: blur(2px);
backdrop-filter: blur(2px);
z-index: 1;
}
nav ul {
display: flex;
align-items: center;
margin: 0;
padding: 0;
list-style: none;
}
nav li {
position: relative;
margin: 0 20px;
height: 50px;
line-height: 50px;
}
nav li ul {
position: absolute;
top: 50px;
left: 0;
flex-direction: column;
align-items: stretch;
width: 200px;
background: hsla(0, 0%, 100%, 80%);
opacity: 0;
-webkit-backdrop-filter: blur(2px);
backdrop-filter: blur(2px);
pointer-events: none;
}
nav li:hover ul {
opacity: 1;
pointer-events: all;
}
nav li li {
margin: 0;
height: 30px;
line-height: 30px;
}<nav>
<ul>
<li>Nav 1</li>
<li>Nav 2</li>
<li>Nav 3
<ul>
<li>Nav 3-1</li>
<li>Nav 3-2</li>
<li>Nav 3-3</li>
</ul>
</li>
</ul>
</nav>
<main>
<h2>What is Lorem Ipsum?</h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It
has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop
publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
<h2>Why do we use it?</h2>
<p>It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here,
content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various
versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).</p>
<h2>Where does it come from?</h2>
<p>Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up
one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum
et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section
1.10.32.</p>
<p>The standard chunk of Lorem Ipsum used since the 1500s is reproduced below for those interested. Sections 1.10.32 and 1.10.33 from "de Finibus Bonorum et Malorum" by Cicero are also reproduced in their exact original form, accompanied by English versions
from the 1914 translation by H. Rackham.</p>
<h2>Where can I get some?</h2>
<p>There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don't look even slightly believable. If you are going to use a passage of Lorem Ipsum,
you need to be sure there isn't anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend to repeat predefined chunks as necessary, making this the first true generator on the Internet. It uses a dictionary
of over 200 Latin words, combined with a handful of model sentence structures, to generate Lorem Ipsum which looks reasonable. The generated Lorem Ipsum is therefore always free from repetition, injected humour, or non-characteristic words etc.</p>
</main>推荐答案
您应避免将 backdrop-filter 应用于子菜单的父元素.想法是考虑在其中可以使用过滤器的伪元素:
You should avoid applying backdrop-filter to a parent element of the sub menu. And idea is to consider a pseudo element where you can have the filter:
nav {
position: fixed;
top: 0;
left: 0;
right: 0;
height: 50px;
background: hsla(0, 0%, 100%, 80%);
border-bottom: 1px solid hsla(0, 0%, 0%, 10%);
z-index: 1;
}
nav:before {
content:"";
position:absolute;
z-index:-1;
-webkit-backdrop-filter: blur(2px);
backdrop-filter: blur(2px);
top:0;
left:0;
right:0;
bottom:0;
}
nav ul {
display: flex;
align-items: center;
margin: 0;
padding: 0;
list-style: none;
}
nav li {
position: relative;
margin: 0 20px;
height: 50px;
line-height: 50px;
}
nav li ul {
position: absolute;
top: 50px;
left: 0;
flex-direction: column;
align-items: stretch;
width: 200px;
background: hsla(0, 0%, 100%, 80%);
opacity: 0;
-webkit-backdrop-filter: blur(2px);
backdrop-filter: blur(2px);
pointer-events: none;
}
nav li:hover ul {
opacity: 1;
pointer-events: all;
}
nav li li {
margin: 0;
height: 30px;
line-height: 30px;
}<nav>
<ul>
<li>Nav 1</li>
<li>Nav 2</li>
<li>Nav 3
<ul>
<li>Nav 3-1</li>
<li>Nav 3-2</li>
<li>Nav 3-3</li>
</ul>
</li>
</ul>
</nav>
<main>
<h2>What is Lorem Ipsum?</h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It
has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop
publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
<h2>Why do we use it?</h2>
<p>It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here,
content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various
versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).</p>
<h2>Where does it come from?</h2>
<p>Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up
one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum
et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section
1.10.32.</p>
<p>The standard chunk of Lorem Ipsum used since the 1500s is reproduced below for those interested. Sections 1.10.32 and 1.10.33 from "de Finibus Bonorum et Malorum" by Cicero are also reproduced in their exact original form, accompanied by English versions
from the 1914 translation by H. Rackham.</p>
<h2>Where can I get some?</h2>
<p>There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don't look even slightly believable. If you are going to use a passage of Lorem Ipsum,
you need to be sure there isn't anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend to repeat predefined chunks as necessary, making this the first true generator on the Internet. It uses a dictionary
of over 200 Latin words, combined with a handful of model sentence structures, to generate Lorem Ipsum which looks reasonable. The generated Lorem Ipsum is therefore always free from repetition, injected humour, or non-characteristic words etc.</p>
</main>此问题与您可以在此处了解的背景根概念有关:https://drafts.fxtf.org/filter-effects-2/#BackdropRoot .您会发现背景过滤器创建了背景根:
The issue is related to the Backdrop Root concept that you can read about here: https://drafts.fxtf.org/filter-effects-2/#BackdropRoot. You will find that back-drop filter create a Backdrop root:
在以下任何情况下，元素在文档中的任何位置形成背景根.有关每个详细信息，请参见§3.2背景根触发器:
A Backdrop Root is formed, anywhere in the document, by an element in any of the following scenarios. See § 3.2 Backdrop Root Triggers for more details on each:
文档(HTML)的根元素.
The root element of the document (HTML).
具有"none"以外的过滤器属性的元素.
An element with a filter property other than "none".
不透明度值小于1的元素.
An element with an opacity value less than 1.
具有mask，mask-image，mask-border或clip-path属性且值为"none"以外的元素.
An element with mask, mask-image, mask-border, or clip-path properties with values other than "none".
具有背景滤镜值(不是"none" )的元素.
具有非正常"混合混合模式值的元素.
An element with a mix-blend-mode value other than "normal".
具有遗嘱值的元素，该元素指定将在非初始值上创建背景根的任何属性.
An element with a will-change value specifying any property that would create a Backdrop Root on non-initial value.
例如，如果父级对其应用了 mix-blend-mode ，则会发生相同的问题.子元素的背景过滤器将不再起作用
If the parent had, for example, mix-blend-mode apply to it, the same issue will happen. The backdrop filter of the child element will no more work
nav {
position: fixed;
top: 0;
left: 0;
right: 0;
height: 50px;
background: hsla(0, 0%, 100%, 80%);
border-bottom: 1px solid hsla(0, 0%, 0%, 10%);
z-index: 1;
-webkit-backdrop-filter: blur(2px);
backdrop-filter: blur(2px);
mix-blend-mode:color;
}
nav ul {
display: flex;
align-items: center;
margin: 0;
padding: 0;
list-style: none;
}
nav li {
position: relative;
margin: 0 20px;
height: 50px;
line-height: 50px;
}
nav li ul {
position: absolute;
top: 50px;
left: 0;
flex-direction: column;
align-items: stretch;
width: 200px;
background: hsla(0, 0%, 100%, 80%);
opacity: 0;
-webkit-backdrop-filter: blur(2px);
backdrop-filter: blur(2px);
pointer-events: none;
}
nav li:hover ul {
opacity: 1;
pointer-events: all;
}
nav li li {
margin: 0;
height: 30px;
line-height: 30px;
}<nav>
<ul>
<li>Nav 1</li>
<li>Nav 2</li>
<li>Nav 3
<ul>
<li>Nav 3-1</li>
<li>Nav 3-2</li>
<li>Nav 3-3</li>
</ul>
</li>
</ul>
</nav>
<main>
<h2>What is Lorem Ipsum?</h2>
<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It
has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop
publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
<h2>Why do we use it?</h2>
<p>It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here,
content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various
versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).</p>
<h2>Where does it come from?</h2>
<p>Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up
one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum
et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section
1.10.32.</p>
<p>The standard chunk of Lorem Ipsum used since the 1500s is reproduced below for those interested. Sections 1.10.32 and 1.10.33 from "de Finibus Bonorum et Malorum" by Cicero are also reproduced in their exact original form, accompanied by English versions
from the 1914 translation by H. Rackham.</p>
<h2>Where can I get some?</h2>
<p>There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don't look even slightly believable. If you are going to use a passage of Lorem Ipsum,
you need to be sure there isn't anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend to repeat predefined chunks as necessary, making this the first true generator on the Internet. It uses a dictionary
of over 200 Latin words, combined with a handful of model sentence structures, to generate Lorem Ipsum which looks reasonable. The generated Lorem Ipsum is therefore always free from repetition, injected humour, or non-characteristic words etc.</p>
</main>这篇关于父元素background-filter不适用于其子元素的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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