js-无缝向上滚动

这种节奏经常用在相同布局内容多的地方，列如排行榜，新闻等地方。为了效率，在此做个笔记

HTML:

<div id="divgd">
        <div id="boxmiddle">
                 <div id="box1samlle">
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                 </div>
                <div id="addbox1"></div>
     </div>
</div>

 

CSS:

#divgd {width: 78%;height: 26rem;overflow: hidden;color: #333;margin: 0 auto;font-size: 1rem;}
#boxmiddle {width: 100%;height: 800%;background: pink;}

#box1samlle,
#addbox1 {float: left;display: block;width: 100%;}

#box1samlle span,
#addbox1 span {float: left;width: 100%;display: block;text-align: center;height: 3rem;line-height: 3rem;}

#box1samlle span label,
#addbox1 span label {display: inline-block;width: 30%;text-align: center;overflow: hidden;text-overflow: ellipsis;white-space: nowrap;}

#box1samlle span label:nth-of-type(1),
#addbox1 span label:nth-of-type(1) {float: left;}

#box1samlle span label:nth-of-type(2),
#addbox1 span label:nth-of-type(2) {float: right;}

JS:

var speed1 = 60;
var demo = document.getElementById("divgd");
var demo1 = document.getElementById("box1samlle");
var demo2 = document.getElementById("addbox1");
demo2.innerHTML = demo1.innerHTML;
     if(document.querySelectorAll("span").length>=20){
          var MyMar = setInterval(Marquee, speed1);
     }else{

     }
    function Marquee() {
           if(demo2.offsetHeight - demo.scrollTop <= 0) {
                 demo.scrollTop -= demo1.offsetHeight
          } else {
                 demo.scrollTop++;
           }
     }

   //下面的一般用在电脑端鼠标事件

    demo.onmouseover = function() {
        clearInterval(MyMar)
    };
    demo.onmouseout = function() {
           MyMar = setInterval(Marquee, speed1);
    }