CSS3动画边框

HTML

<p>提示：请将鼠标指向图片查看效果</p>
<div id="demo">
    <div class="animation_border"></div>
    <img src="img/4.jpg" width="300" height="180" alt="" /> </div>
</body>
					    

CSS

* {
    margin: 0;
    padding: 0;
}
#demo {
    width: 300px;
    padding: 10px;
    position: absolute;
    left: 200px;
    top: 100px;
}
#demo > img {
    display: block;
    position: relative;
    cursor: pointer;
}
#demo:hover .animation_border { opacity: 1; }
.animation_border {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0;
    -webkit-transition: opacity 0.3s ease;
    -moz-transition: opacity 0.3s ease;
    transition: opacity 0.3s ease;
    background-size: 30px 30px;
    background-image: -webkit-linear-gradient(45deg, red 25%, transparent 25%, transparent 50%, red 50%, red 75%, transparent 75%, transparent);
    background-image: -moz-linear-gradient(45deg, red 25%, transparent 25%, transparent 50%, red 50%, red 75%, transparent 75%, transparent);
    background-image: linear-gradient(45deg, red 25%, transparent 25%, transparent 50%, red 50%, red 75%, transparent 75%, transparent);
    -webkit-animation: animate 0.5s linear infinite;
    -moz-animation: animate 0.5s linear infinite;
    animation: animate 0.5s linear infinite;
}
@-webkit-keyframes animate {
    from {
        background-position: 0 0;
    }
    to {
        background-position: 60px 30px;
    }
    }
@-moz-keyframes animate {
    from {
        background-position: 0 0;
    }
    to {
        background-position: 60px 30px;
    }
}
@keyframes animate {
    from {
        background-position: 0 0;
    }
    to {
        background-position: 60px 30px;
    }
}