<div class="code-bg">

    <div class="line"></div>

</div>

.code-bg{

		    position: relative;

		    height: 200px; width: 200px;

		    margin: 0px auto;/*此处为了居中*/

		    background: url(img/ewm1.jpg) center top no-repeat; /*二维码*/

		}

		.line{

		    position: absolute;

		    left: -80px;

		    z-index: 2;

		    height: 3px; width: 360px;

		    background: url(img/share/dapai.png) no-repeat; /*上下扫的线*/

		    /*动画效果*/

		    animation: myScan 1s infinite alternate;

		    -webkit-animation: myScan 1s infinite alternate;

		}

		@keyframes  myScan{

		    from { top:0px; }

		    to { top: 197px; }

		}

		-webkit-@keyframes  myScan{

		    from { top:0px; }

		    to { top: 197px; }

		}