.item:hover {
zoom: 1;
filter: alpha(opacity=50);
opacity: 0.5;
-webkit-transition: opacity .15s ease-in-out;
-moz-transition: opacity .15s ease-in-out;
-ms-transition: opacity .15s ease-in-out;
-o-transition: opacity .15s ease-in-out;
transition: opacity .15s ease-in-out;
}
为什么这只是动画的不透明度，当我悬停，但不是当我离开的对象与鼠标？
解决方法
您只将转换应用于：hover伪类，而不是元素本身。
.item {
height:200px;
width:200px;
background:red;
-webkit-transition: opacity 1s ease-in-out;
-moz-transition: opacity 1s ease-in-out;
-ms-transition: opacity 1s ease-in-out;
-o-transition: opacity 1s ease-in-out;
transition: opacity 1s ease-in-out;
}
.item:hover {
zoom: 1;
filter: alpha(opacity=50);
opacity: 0.5;
}
演示：http://jsfiddle.net/7uR8z/6/
如果不希望转换影响鼠标悬停事件，而只想要鼠标悬停事件，则可以为：hover状态关闭转场：
.item:hover {
-webkit-transition: none;
-moz-transition: none;
-ms-transition: none;
-o-transition: none;
transition: none;
zoom: 1;
filter: alpha(opacity=50);
opacity: 0.5;
}
