为什么我的CSS:悬停@keyframes动画不起作用？

Question

我是新手.为什么这段代码不起作用？我想让鸟儿飞翔.

我的HTML:

<img src="http://dl.dropboxusercontent.com/u/105046436/tw.png" />
<br>
<div class="twitter-bird"></div>

我的CSS:

.twitter-bird {
    background-image: url(http://dl.dropboxusercontent.com/u/105046436/tw.png);
    display: inline-block;
    height: 38px;
    width: 37.5px;
}

.twitter-bird:hover {
    animation: fly 0.2s steps(3) 0 infinite;
}

@keyframes fly {
    from { background-position: 0 0; }
    to { background-position: -112.5px 0; }
}

JSFiddle:http://jsfiddle.net/6qHMG/

我想要的是:

我想改变图像的背景位置.

怎么了:

悬停时图像位置不会改变.

编辑:我认为背景图像位置没有正确改变.背景位置似乎没有改变.如何设置background-position:的@keyframes fly？

Answer 1

这里是:

你必须添加供应商前缀

.twitter-bird {
    height: 38px;
    width: 37.5px;
    background-image: url("http://dl.dropboxusercontent.com/u/105046436/tw.png");
}

.twitter-bird:hover { 
    -webkit-animation: fly .4s steps(3) infinite;
       -moz-animation: fly .4s steps(3) infinite;
        -ms-animation: fly .4s steps(3) infinite;
         -o-animation: fly .4s steps(3) infinite;
            animation: fly .4s steps(3) infinite;
}

@-webkit-keyframes fly {
   from { background-position:    0px; }
     to { background-position: -112.5px; }
}

@-moz-keyframes fly {
   from { background-position:    0px; }
     to { background-position: -112.5px; }
}

@-ms-keyframes fly {
   from { background-position:    0px; }
     to { background-position: -112.5px; }
}

@-o-keyframes fly {
   from { background-position:    0px; }
     to { background-position: -112.5px; }
}

@keyframes fly {
   from { background-position:    0px; }
     to { background-position: -112.5px; }
}

小提琴:http://jsfiddle.net/6qHMG/4/