每当我悬停其父元素时，我一直在尝试使用 css 来显示隐藏的 Div 淡入。
到目前为止，我所能做的就是让隐藏的 div 显示出来，但是从来没有缓和过渡。
这是我在 JSfiddle 上的代码 http://jsfiddle.net/9dsGP/
这是我的代码:
HTML:
<div id="header">
<div id="button">This is a Button
<div class="content">
This is the Hidden Div
</div>
</div>
</div>
CSS:
#header #button {width:200px; background:#eee}
#header #button:hover > .content {display:block; opacity:1;}
#header #button .content:hover { display:block;}
#header #button .content {
-webkit-transition: all .3s ease .15s;
-moz-transition: all .3s ease .15s;
-o-transition: all .3s ease .15s;
-ms-transition: all .3s ease .15s;
transition: all .3s ease .15s;
opacity:0;
clear: both;
display: none;
top: -1px;
left:-160px;
padding: 8px;
min-height: 150px;
border-top: 1px solid #EEEEEE;
border-left: 1px solid #EEEEEE;
border-right: 1px solid #EEEEEE;
border-bottom: 1px solid #EEEEEE;
-webkit-border-radius: 0px 7px 7px 7px;
-moz-border-radius: 0px 7px 7px 7px;
-khtml-border-radius: 0px 7px 7px 7px;
border-radius: 0px 7px 7px 7px;
-webkit-box-shadow: 0px 2px 2px #DDDDDD;
-moz-box-shadow: 0px 2px 2px #DDDDDD;
box-shadow: 0px 2px 2px #DDDDDD;
background: #FFF;
}
关于我做错了什么的任何线索？当我将鼠标悬停在按钮上时，只是想为隐藏的内容获得平滑效果。提前致谢!
display:none; removes a block from the page as if it were never there.
A block cannot be partially displayed; it’s either there or it’s not.
The same is true for visibility; you can’t expect a block to be half
hidden which, by definition, would be visible! Fortunately, you can
use opacity for fading effects instead.
- reference
作为替代 CSS 解决方案，您可以使用 opacity、height 和 padding 属性来达到理想的效果:
#header #button:hover > .content {
opacity:1;
height: 150px;
padding: 8px;
}
#header #button .content {
opacity:0;
height: 0;
padding: 0 8px;
overflow: hidden;
transition: all .3s ease .15s;
}
(为简洁起见省略了供应商前缀。)
这是一个 working demo 。这里还有a similar topic在 SO 上。
#header #button {
width:200px;
background:#ddd;
transition: border-radius .3s ease .15s;
}
#header #button:hover, #header #button > .content {
border-radius: 0px 0px 7px 7px;
}
#header #button:hover > .content {
opacity: 1;
height: 150px;
padding: 8px;
}
#header #button > .content {
opacity:0;
clear: both;
height: 0;
padding: 0 8px;
overflow: hidden;
-webkit-transition: all .3s ease .15s;
-moz-transition: all .3s ease .15s;
-o-transition: all .3s ease .15s;
-ms-transition: all .3s ease .15s;
transition: all .3s ease .15s;
border: 1px solid #ddd;
-webkit-box-shadow: 0px 2px 2px #ddd;
-moz-box-shadow: 0px 2px 2px #ddd;
box-shadow: 0px 2px 2px #ddd;
background: #FFF;
}
#button > span { display: inline-block; padding: .5em 1em }
<div id="header">
<div id="button"> <span>This is a Button</span>
<div class="content">
This is the Hidden Div
</div>
</div>
</div>