CSS 如何通过 CSS3 动画淡入背景图像
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How to fade in background image by CSS3 Animation
提问by Alex Jj
I am making a menu that each item has a text like item1, item2 and etc. in hover the background colour changes, text becomes transparent and a background image replaces. I used this code to ease in and out the style. but it only works for background colour and not the image.
我正在制作一个菜单，每个项目都有一个文本，如 item1、item2 等。悬停时背景颜色发生变化，文本变得透明，背景图像被替换。我使用此代码来缓入和缓出样式。但它只适用于背景颜色而不是图像。
#nav li:hover {
color:transparent !important;
text-shadow: none;
background-color: rgba(255, 0, 0, .5);
-webkit-transition: all 1s ease-in;
-moz-transition: all 1s ease-in;
-o-transition: all 1s ease-in;
-ms-transition: all 1s ease-in;
transition: all 1s ease-in;
}
Here is the online version: http://jsfiddle.net/q4uHz/
这是在线版本：http: //jsfiddle.net/q4uHz/
回答by Explosion Pills
Background images cannot be animated; there would be no algorithm for that. A simple solution is to include <img>with the icon in your HTML instead with opacity: 0and animate that. Something like.
背景图像不能动画；没有算法可以解决这个问题。一个简单的解决方案是<img>在 HTML 中包含图标，而不是使用它opacity: 0并为其设置动画。就像是。
<li id="home">
<img src="http://cdn3.iconfinder.com/data/icons/picons-social/57/16-apple-48.png">
<a href="#home">Home</a></li>
#nav li {
position: relative;
}
#nav li img {
opacity: 0;
position: absolute;
transition: all 1s ease-in;
top: 0;
left: 0;
}
#nav li:hover img {
opacity: 1;
}
