Question

在以下示例中，我有两个元素。一个有内容部分的背景图像，另一个没有。两个标头都有box-shadow属性。如何在背景图像设置的元素上方显示阴影？

.testcontainer {
  width: 200px;
  display: inline-block;
  border: 1px solid gray;
  height: 120px;
}

.header {
  height: 20px;
  background-color: cornflowerblue;
  color: white;
    -webkit-box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
          box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
}

.content {
  height: 100px;
}

#hasbgimage {
  background-image: url("https://via.placeholder.com/200x100");
  background-size: cover;
}

<div class="testcontainer">
  <div class="header">test with no image</div>
  <div class="content"></div>
</div>
<div class="testcontainer">
  <div class="header">test with image</div>
  <div class="content" id="hasbgimage"></div>
</div>

Answer 1

您只需为#hasbgimage

定义插入阴影即可

＆＃13;

.testcontainer {
  width: 200px;
  display: inline-block;
  border: 1px solid gray;
  height: 120px;
}

.header {
  height: 20px;
  background-color: cornflowerblue;
  color: white;
    -webkit-box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
          box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
}

.content {
  height: 100px;
}

#hasbgimage {
  background-image: url("https://via.placeholder.com/200x100");
  background-size: cover;
    -webkit-box-shadow: inset 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
          box-shadow: inset 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
}

＆＃13;

<div class="testcontainer">
  <div class="header">test with no image</div>
  <div class="content"></div>
</div>
<div class="testcontainer">
  <div class="header">test with image</div>
  <div class="content" id="hasbgimage"></div>
</div>

＆＃13;

Answer 2

您只需将z-index添加到第一个元素即可将其box-shadow添加到上面

＆＃13;

.testcontainer {
  width: 200px;
  display: inline-block;
  border: 1px solid gray;
  height: 120px;
}

.header {
  position:relative; /*And don't forget this !!!*/
  z-index:2;
  height: 20px;
  background-color: cornflowerblue;
  color: white;
    -webkit-box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
          box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
}

.content {
  height: 100px;
}

#hasbgimage {
  background-image: url("https://via.placeholder.com/200x100");
  background-size: cover;
}

＆＃13;

<div class="testcontainer">
  <div class="header">test with no image</div>
  <div class="content"></div>
</div>
<div class="testcontainer">
  <div class="header">test with image</div>
  <div class="content" id="hasbgimage"></div>
</div>

＆＃13;

Answer 3

添加子div并在其上设置背景图像，因此它不会覆盖框阴影。

.testcontainer {
  width: 200px;
  display: inline-block;
  border: 1px solid gray;
  height: 120px;
}

.header {
  position:relative; /*And don't forget this !!!*/
  z-index:2;
  height: 20px;
  background-color: cornflowerblue;
  color: white;
    -webkit-box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
          box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
}

.content {
  height: 100px;
}

#hasbgimage {
  background-image: url("https://via.placeholder.com/200x100/aabbcc/");
  background-size: cover;
  height:100%;
  width:100%;
}

<div class="testcontainer">
  <div class="header">test with no image</div>
  <div class="content"></div>
</div>
<div class="testcontainer">
  <div class="header">test with image</div>
  <div class="content">
    <div  id="hasbgimage"></div>
  </div>
</div>

阴影与背景图像元素？

3 个答案: