JavaScript实现文字跑马灯效果

项目开发中若需要做系统公告，可在此Demo的基础上稍加修改实现一个简单的系统公告效果

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>文字跑马灯</title>
    <style>
        #race_notice_p{
            position:relative;
            margin:20px auto;
            width:800px;
            overflow:hidden;
            height:50px;
        }
        #race_notice_s{
            position:absolute;
            left:0;
            top:0;
        }
        #race_notice_s p span{
            margin:0 20px;
            line-height: 50px;
        }
    </style>
</head>
<body>
    <div id='race_notice_p' >
        <div id='race_notice_s'>
            <p>
                <span>本文主要分享了原生JS实现跑马灯效果的示例代码。看，这就是跑马灯效果</span>
            </p>
        </div>
    </div>
</body>
    <script>
        window.onload=function(){
            function move(){
                var speed = -5;
                var race_notice_p = document.getElementById('race_notice_p');
                var race_notice_s = document.getElementById('race_notice_s');
                var p = race_notice_s.getElementsByTagName('p')[0];
                var length = p.offsetWidth;
                p.innerHTML +=p.innerHTML;
                function move_do(){
                    if(race_notice_s.offsetLeft < - length){
                        race_notice_s.style.left=0;
                    }
                    race_notice_s.style.left = race_notice_s.offsetLeft + speed +'px';
                }
                setInterval(move_do,200);
            }
            move();
        }
    </script>
</html>