我想让左边往右边拖动的时候越来越慢最后拖不动,右边往左边拖也是,现在只实现了左到右,右到左该怎么弄
<!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> <style> #show {width:600px;height:400px;overflow:hidden;position: relative;margin:0 auto;border:1px solid #000;} #drag{width:1000px;height:400px;position: absolute;top:0;left:0;background:pink;} </style> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> <script> window.onload=function(){ drag("show","drag"); } function drag(parentObj,obj){ var obj=document.getElementById(obj); var Roadwidth=document.getElementById(parentObj); var scrwidth=1000; var disX=0; var downX=0; obj.onmousedown=function(ev){ var ev=ev||event; disX=ev.clientX-obj.offsetLeft; downX=ev.clientX; clearInterval(obj.timer); document.onmousemove=function(ev){ var ev=ev||event; obj.style.left=(ev.clientX-disX)/3+"px"; }; document.onmouseup=function(ev){ document.onmousemove=null; document.onmouseup=null; var ev=ev||event; if(ev.clientX<downX){ startMove(obj,{left:-(scrwidth-Roadwidth.clientWidth)}) }else{ startMove(obj,{left:0}) } }; return false; } } function getStyle(obj,attr){ if(obj.currentStyle){return obj.currentStyle[attr];} else{return getComputedStyle(obj,false)[attr];} } function startMove(obj,json,fn){ clearInterval(obj.timer); obj.timer=setInterval(function(){ var bStop=true; for(var attr in json){ var iCur=0; iCur=parseInt(getStyle(obj,attr)); var iSpeed=(json[attr]-iCur)/8; iSpeed=iSpeed>0?Math.ceil(iSpeed):Math.floor(iSpeed); if(iCur!=json[attr]){ bStop=false; } obj.style[attr]=iCur+iSpeed+"px"; } if(bStop){ clearInterval(obj.timer); if(fn){fn();} } },30); } </script> </head> <body> <div id="show"> <div id="drag"> </div> </div> </body> </html>