JS图片纵向滚动滚了一会儿停住了

Question

 <div id="rollpic" style="overflow:hidden; width:150px; height:300px">
                     <div id="demo1">
                         <a href="#"><img src="images/flogo1.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo2.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo3.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo4.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo5.jpg" width="96" height="49" alt="f" /></a>
                     </div>
<div id="demo2"></div>
</div>
<script>
          var speed=30;
          var tab=document.getElementById("rollpic");
          var tab1=document.getElementById("demo1");
          var tab2=document.getElementById("demo2");
          tab2.innerHTML=tab1.innerHTML;
          function Marquee(){
          if(tab2.offsetHeight-tab.scrollTop<0)
          tab.scrollTop-=tab2.offsetHeight;
          else{
          tab.scrollTop++;
          }
          }
          var MyMar=setInterval(Marquee,speed);
          tab.onmouseover=function() {clearInterval(MyMar)};
          tab.onmouseout=function() {MyMar=setInterval(Marquee,speed)};
</script>
滚了几遍就停下来了，怎么办？

Answer 1

 <div id="rollpic" style="overflow:hidden; width:150px; height:300px">
                     <div id="demo1">
                         <a href="#"><img src="images/flogo1.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo2.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo3.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo4.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo5.jpg" width="96" height="49" alt="f" /></a>  <a href="#"><img src="images/flogo1.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo2.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo3.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo4.jpg" width="96" height="49" alt="f" /></a>
                         <a href="#"><img src="images/flogo5.jpg" width="96" height="49" alt="f" /></a>
                     </div>
<div id="demo2"></div>
</div>

Answer 2

if(tab2.offsetHeight-tab.scrollTop<=56){

Answer 3

在tab2.offsetHeight-tab.scrollTop==56的时候停止了滚动

Answer 4

就是56，你图片停止的时候tab2.offsetHeight-tab.scrollTop等于56

Answer 5

overflow:hidden 改为 overflow:scroll
多加点图片，正常滚动时，看看滚动条的变化规律，这样理解起来比较直观。

Answer 6

overflow:hidden 改为 overflow:scroll
多加点图片，正常滚动时，看看滚动条的变化规律，这样理解起来比较直观。