js实现带按钮的上下滚动效果

2019-11-20 12:30:00

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本文实例讲述了js实现带按钮的上下滚动效果。分享给大家供大家参考。具体实现方法如下：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>js带按钮上下滚动效果</title><style type="text/css">ul{ margin:0; padding:0; list-style:none; height:100000px;}li{ margin:0; padding:0; width:100px; height:100px; display:block; float:top; margin-bottom:5px; background:#009900;}#img_bag{ width:110px; height:600px; background:#F2F2F2; margin:0 auto; text-align:center;}#img_bag #img{ width:100px; height:525px; background:#969696; overflow:hidden; margin:auto;}</style></head><body><div id="img_bag"> <a href="javascript:void(0)" onmousedown="moveTop()"> <img src="upp.jpg" border="0" /></a> <div id="img"> <ul>  <li>1</li>  <li>2</li>  <li>3</li>  <li>4</li>  <li>5</li>  <li>6</li>  <li>7</li>  <li>8</li>  <li>9</li>  <li>10</li>  <li>11</li>  <li>12</li> </ul> </div> <a href="javascript:void(0)" onmousedown="moveBottom()"> <img src="down.jpg" border="0" /></a></div><script type="text/javascript">function $(obj){ //获取指定对象 return document.getElementById(obj);}var maxHeight=$("img").getElementsByTagName("ul")[0].getElementsByTagName("li").length*105;//滚动图片的最大高度var targety = 211;//一次滚动距离var dx;var a=null;function moveTop(){ var le=parseInt($("img").scrollTop); if(le>211){ targety=parseInt($("img").scrollTop)-211; }else{ targety=parseInt($("img").scrollTop)-le-1; } scTop();}function scTop(){ dx=parseInt($("img").scrollTop)-targety; $("img").scrollTop-=dx*.3; clearScroll=setTimeout(scTop,50); if(dx*.3<1){ clearTimeout(clearScroll); }}function moveBottom(){ var le=parseInt($("img").scrollTop)+211; var maxL=maxHeight-600; if(le<maxL){ targety=parseInt($("img").scrollTop)+211; }else{ targety=maxL } scBottom();}function scBottom(){ dx=targety-parseInt($("img").scrollTop); $("img").scrollTop+=dx*.3; a=setTimeout(scBottom,50); if(dx*.3<1){ clearTimeout(a) }}</script></body></html>

运行效果如下所示：