有没有办法实现在元素上设置CSS filter: brightness()的效果，而不会影响特定/全部（无关紧要）子元素？
考虑以下示例：
function setBrightness (bright) {
$('.icon').css('filter', `brightness(${bright})`);
// None of these work:
// $('.indicator').css('filter', '');
// $('.indicator').css('filter', 'brightness(1.0)');
// $('.indicator').css('filter', `brightness(${1.0/bright})`);
}
window.setInterval(function () {
let ms = new Date().getTime();
let bright = Math.cos(2.0 * 3.14 * ms / 3000.0) + 1.0;
setBrightness(bright);
}, 50);#bar {
background: #222;
font-size: 0;
}
.icon {
background-image: url(https://cdn.sstatic.net/img/share-sprite-new.svg?v=78be252218f3);
width: 36px;
height: 34px;
display: table-cell;
text-align: center;
/* normally middle but set to top to not obscure background for this example: */
vertical-align: top;
}
.icon1 {
background-position: -141px -54px;
}
.icon2 {
background-position: -220px -54px;
}
.indicator {
border-radius: 2px;
color: white;
display: inline-block;
font-family: sans-serif;
font-size: 8pt;
width: 50%;
}
.icon1 .indicator {
background: #a00;
}
.icon2 .indicator {
background: #0f0;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<body>
<div id="bar">
<div class="icon icon1">
<span class="indicator">3</span>
</div>
<div class="icon icon2">
<span class="indicator">10</span>
</div>
</div>
</body>
在这里，我在span（类div）中有一个icon，我在div上设置过滤器亮度，如下所示：
$('.icon').css('filter', `brightness(${bright})`);
但是，我希望仅影响该背景，而不会影响小“指标”span。也就是说，在上面的代码片段中，图标应该是脉冲式的，但前景指示符及其红色/绿色背景应保持不变。我想到的唯一尝试失败的事情是：
function setBrightness (bright) {
$('.icon').css('filter', `brightness(${bright})`);
// None of these work:
// $('.indicator').css('filter', '');
// $('.indicator').css('filter', 'brightness(1.0)');
// $('.indicator').css('filter', `brightness(${1.0/bright})`);
}
此外，我不对以下内容进行更改非常重要：
background-* CSS属性。span必须仍为div的子级。顺便说一句，我实际上并不需要省略所有子元素的解决方案。我只需要一个给定的孩子（那些span）不受影响，因为我正在使用的结构在每个div下没有多个孩子;这个例子具有代表性。不确定这是否重要。
有办法做到这一点吗？
答案 0 :(得分：1)
更改父元素的不透明度将始终更改子元素的不透明度。可悲的是，没有办法解决这个问题。但是，您可以更改HTML结构并将元素绝对定位在彼此之上，然后仅定位您想要淡化的元素。
$(document).ready(function(){
function setBrightness (bright) {
$('.icon').css('filter', `brightness(${bright})`);
}
window.setInterval(function () {
let ms = new Date().getTime();
let bright = Math.cos(2.0 * 3.14 * ms / 3000.0) + 1.0;
setBrightness(bright);
}, 50);
});#bar {
background: #222;
font-size: 0;
}
.icon {
background-image: url(https://cdn.sstatic.net/img/share-sprite-new.svg?v=78be252218f3);
width: 36px;
height: 34px;
display: inline-block;
position: absolute;
top:0;
left: 0;
}
.icon-wrap {
width: 36px;
height: 34px;
text-align: center;
position: relative;
display: table-cell;
/* normally middle but set to top to not obscure background for this example: */
}
.icon1 .icon {
background-position: -141px -54px;
}
.icon2 .icon {
background-position: -220px -54px;
}
.indicator {
border-radius: 2px;
color: white;
font-family: sans-serif;
font-size: 8pt;
width: 18px;
height: 14px;
position: absolute;
top:0;
left:50%;
margin-left: -9px;
}
.icon1 .indicator {
background: #a00;
}
.icon2 .indicator {
background: #0f0;
}<div id="bar">
<div class="icon1 icon-wrap">
<span class="icon"></span>
<span class="indicator">3</span>
</div>
<div class="icon2 icon-wrap">
<span class="icon"></span>
<span class="indicator">10</span>
</div>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>
也可以使用CSS3关键帧：
#bar {
background: #222;
font-size: 0;
}
.icon {
background-image: url(https://cdn.sstatic.net/img/share-sprite-new.svg?v=78be252218f3);
width: 36px;
height: 34px;
display: inline-block;
position: absolute;
top:0;
left: 0;
-webkit-filter: grayscale(200%); /* Safari 6.0 - 9.0 */
filter: grayscale(200%);
}
.icon-wrap {
width: 36px;
height: 34px;
text-align: center;
position: relative;
display: table-cell;
/* normally middle but set to top to not obscure background for this example: */
}
.icon1 .icon {
background-position: -141px -54px;
}
.icon2 .icon {
background-position: -220px -54px;
}
.indicator {
border-radius: 2px;
color: white;
font-family: sans-serif;
font-size: 8pt;
width: 18px;
height: 14px;
position: absolute;
top:0;
left:50%;
margin-left: -9px;
}
.icon1 .indicator {
background: #a00;
}
.icon2 .indicator {
background: #0f0;
}
@keyframes fader {
0% {
-webkit-filter: grayscale(200%); /* Safari 6.0 - 9.0 */
filter: grayscale(200%);
}
50% {
-webkit-filter: grayscale(0%); /* Safari 6.0 - 9.0 */
filter: grayscale(0%);
}
100% { opacity:1;
-webkit-filter: grayscale(200%); /* Safari 6.0 - 9.0 */
filter: grayscale(200%);
}
}
@-o-keyframes fader {
0% {
-webkit-filter: brightness(200%); /* Safari 6.0 - 9.0 */
filter: brightness(200%);
}
50% {
-webkit-filter: brightness(0%); /* Safari 6.0 - 9.0 */
filter: brightness(0%);
}
100% { opacity:1;
-webkit-filter: brightness(200%); /* Safari 6.0 - 9.0 */
filter: brightness(200%);
}
}
@-moz-keyframes fader {
0% {
-webkit-filter: brightness(200%); /* Safari 6.0 - 9.0 */
filter: brightness(200%);
}
50% {
-webkit-filter: brightness(0%); /* Safari 6.0 - 9.0 */
filter: brightness(0%);
}
100% { opacity:1;
-webkit-filter: brightness(200%); /* Safari 6.0 - 9.0 */
filter: brightness(200%);
}
}
@-webkit-keyframes fader {
0% {
-webkit-filter: brightness(200%); /* Safari 6.0 - 9.0 */
filter: brightness(200%);
}
50% {
-webkit-filter: brightness(0%); /* Safari 6.0 - 9.0 */
filter: brightness(0%);
}
100% { opacity:1;
-webkit-filter: brightness(200%); /* Safari 6.0 - 9.0 */
filter: brightness(200%);
}
}
.icon {
-webkit-animation: fader 3s infinite ease-in;
-moz-animation: fader 3s infinite ease-in;
-o-animation: fader 3s infinite ease-in;
animation: fader 3s infinite ease-in;
}<div id="bar">
<div class="icon1 icon-wrap">
<span class="icon"></span>
<span class="indicator">3</span>
</div>
<div class="icon2 icon-wrap">
<span class="icon"></span>
<span class="indicator">10</span>
</div>
</div>