如何创建黑色透明叠加/模态对话框与居中文本在图像上

Question

我想在悬停的图像上创建一个黑色透明的叠加，并将文本居中。有点像Instagram在这里听到的每张图片(悬停在图片上)

我试过这样做:

.parent {
  position: relative;
  background: black;
}
.child {
  position: absolute;
  top: 50%;
  left: 50%;
  margin-right: -50%;
  transform: translate(-50%, -50%);
  visibility: hidden;
}
.child p {
  text-align: center;
  color: white;
  font-size: 1.2em;
}
.child:hover {
  visibility: visible;
  opacity: 4;
}

<div class="parent">
  <img src="someimageurl">
  <div class="child">
    <p>some text</p>
  </div>
</div>

这已经惨败了。请注意，该解决方案还应适用于视频标签。

Answer 1

尝试如下:

1. 给你的容器一个相对位置
2. 将display: flex;、justify-content: center;、align-items: center;和position: absolute;分配到您的模态
隐藏覆盖使用background-color: rgba(0, 0, 0, 0);和显示它与background-color: rgba(0, 0, 0, 0.5);悬停。(使用rgba()不会分配文本的不透明度，这就是为什么你应该使用它的不透明度)隐藏文本，你可以使用visibility: hidden;和visibility: visible;来显示它。

.container {
  width: 300px;
  height: 300px;
  position: relative;
  font-family: Helvetica,sans-serif;
}
img {
  background-color: red;
  width: 300px;
  height: 300px;
}
.overlay {
  display: flex;
  justify-content: center;
  align-items: center;
  color: red;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  top: 0;
  background-color: rgba(0, 0, 0, 0);
  visibility: hidden;
}
.container:hover > .overlay {
  background-color: rgba(0, 0, 0, 0.5);
  visibility: visible;
}

<div class="container">
  <img src="https://i.stack.imgur.com/Zw1MI.jpg"/>
  <div class="overlay">Darth Maul</div>
</div>

Answer 2

您可以考虑渐入式和滑下式的变化。运行下面的代码片段。

.child p {
    width: 100%;
    text-align: center;
    font-size: 1.2em;
    margin: auto;
    top: 45%;
    position: absolute;
}
.child {
    position: absolute;
    right: 0;
    left: 0;
    visibility: hidden;
    color: transparent;
    top: 0;
    bottom: 0;
    max-width: 100%;
    max-height: 300px;
    display: block;
    vertical-align: middle;
    transition: .7s;
}
.parent {
    position: relative;
    width: auto;
    display: block;
    max-width: 300px;
    overflow: hidden;
}
.parent:hover .child {
    visibility: visible;
    opacity: .4;
    background: black;
    color: white;
}
.parent:hover .child.slide-down {
    top: 0;
}
.child.slide-down {
    top: -500px;
}

<div class="parent">
     <img src="https://placeholdit.imgix.net/~text?txtsize=28&txt=300%C3%97300&w=300&h=300">
    <div class="child">
     <p>some text</p>
    </div>
</div>
<div class="parent">
     <img src="https://placeholdit.imgix.net/~text?txtsize=28&txt=300%C3%97300&w=300&h=300">
    <div class="child slide-down">
     <p>some text</p>
    </div>
</div>

Answer 3

我认为一个简单的方法是让图像"cover"已经在那里，但隐藏，直到鼠标悬停:

#parentdiv { background-image:url('myimage.jpg'); }
#parentdiv div { width:100%; height: 100%; opacity:0.2; background: #000; text-align:center; display: none; }

与HTML一样

<div id="parentdiv">
    <div><!-- text icons in here --></div>
</div>

和javascript:

document.getElementById("parentdiv").addEventListener("mouseover", function () {
    this.children[0].style.display = 'block';
});

和鼠标移出:

document.getElementById("parentdiv").addEventListener("mouseout", function () {
    this.children[0].style.display = 'none';
});