我的答案不是关于静态的父子布局，而是关于动画。

I was doing an svg demo today, and i needed svg to be inside div (because svg is created with parent's div width and height, to animate the path around), and this parent div needed to be invisible during svg path animation (and then this div was supposed to animate opacity from 0 to 1, it's the most important part). And because parent div with opacity: 0 was hiding my svg, i came across this hack with visibility option (child with visibility: visible can be seen inside parent with visibility: hidden):

.main.invisible .test {
  visibility: hidden;
}
.main.opacity-zero .test {
  opacity: 0;
  transition: opacity 0s !important;
}
.test { // parent div
  transition: opacity 1s;
}
.test-svg { // child svg
  visibility: visible;
}

然后，在js中，你用timeout函数删除。invisible类，添加。opaque -zero类，用。style。top之类的东西触发布局;并删除。opaque - 0类。

var $main = $(".main");
  setTimeout(function() {
    $main.addClass('opacity-zero').removeClass("invisible");
    $(".test-svg").hide();
    $main.css("top");
    $main.removeClass("opacity-zero");
  }, 3000);

最好检查这个演示http://codepen.io/suez/pen/54bbb2f09e8d7680da1af2faa29a0aef?editors=011

正如其他人在这篇文章和其他类似的文章中提到的，避免这个问题的最好方法是使用RGBA/HSLA或使用透明的PNG。

但是，如果你想要一个荒谬的解决方案，类似于这个线程(这也是我的网站)中另一个答案中的链接，这里有一个全新的脚本，我写了一个自动修复这个问题，称为thatsNotYoChild.js:

http://www.impressivewebs.com/fixing-parent-child-opacity/

基本上，它使用JavaScript从父div中删除所有子元素，然后将子元素重新定位到它们应该在的位置，而不再是该元素的子元素。

对我来说，这应该是最后的手段，但我认为如果有人想这样做的话，写一些这样的东西会很有趣。

这个问题没有定义背景是颜色还是图像，但由于@Blowski已经回答了彩色背景，下面有一个针对图像的破解方法:

background: linear-gradient(rgba(0,0,0,.6), rgba(0,0,0,.6)), url('image.jpg');

这样你就可以操纵不透明度的颜色，甚至添加漂亮的渐变效果。

.wrapper { 宽度:630 px; 身高:420 px; 显示:表; 背景:线性渐变( rgba(0, 0, 0, 0。8), rgba(0, 0, 0, 0。8)), url (http://cdn.moviestillsdb.com/sm/35bc3c6a2b791425de6caf8b9391026e/rambo-iii.jpg); ｝ h1 { 显示:表格单元; vertical-align:中间; text-align:中心; 颜色:# fff; ｝ < div class = "包装" > <标题> 5770341 < / h1 >问题 < / div >

我的答案不是关于静态的父子布局，而是关于动画。

I was doing an svg demo today, and i needed svg to be inside div (because svg is created with parent's div width and height, to animate the path around), and this parent div needed to be invisible during svg path animation (and then this div was supposed to animate opacity from 0 to 1, it's the most important part). And because parent div with opacity: 0 was hiding my svg, i came across this hack with visibility option (child with visibility: visible can be seen inside parent with visibility: hidden):

.main.invisible .test {
  visibility: hidden;
}
.main.opacity-zero .test {
  opacity: 0;
  transition: opacity 0s !important;
}
.test { // parent div
  transition: opacity 1s;
}
.test-svg { // child svg
  visibility: visible;
}

然后，在js中，你用timeout函数删除。invisible类，添加。opaque -zero类，用。style。top之类的东西触发布局;并删除。opaque - 0类。

var $main = $(".main");
  setTimeout(function() {
    $main.addClass('opacity-zero').removeClass("invisible");
    $(".test-svg").hide();
    $main.css("top");
    $main.removeClass("opacity-zero");
  }, 3000);

最好检查这个演示http://codepen.io/suez/pen/54bbb2f09e8d7680da1af2faa29a0aef?editors=011

如果你的父类是透明的，并且你希望你的子类是相同的，但是是专门定义的(例如覆盖一个选择下拉菜单的用户代理样式)，有一个小技巧:

.parent {
     background-color: rgba(0,0,0,0.5);
}

.child {
     background-color: rgba(128,128,128,0);
}

<!--Background opacity--> <style> .container1 { width: 200px; height: 200px; background: rgba(0, 0, 0, .5); margin-bottom: 50px; } </style> <div class="container1"> <div class="box1">Text</div> </div> <!--Before, after, z-index opacity--> <style> .container2 { width: 200px; height: 200px; position: relative; margin-bottom: 100px; } .container2:after { content: ''; display: block; width: 100%; height: 100%; position: absolute; top: 0; left: 0; background: black; opacity: .5; z-index: 1; } .box2 { position: relative; z-index: 2; } </style> <div class="container2"> <div class="box2">Text</div> </div> <!--Outline opacity--> <style> .container3 { width: 200px; height: 200px; outline: 50px solid rgba(0, 0, 0, .5); margin: 50px; } .box3 { position: relative; left: -16px; } </style> <div class="container3"> <div class="box3">Text</div> </div>