<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title></title> <style> #progress{ position: relative; margin: auto; top: 200px; display: block; 200px; height: 20px; border-style: dotted; border- thin; border-color: darkgreen; } #filldiv{ position: absolute; top: 0px; left: 0px; 0px; height: 20px; background: blue; } #percent{ position: absolute; top: 0px; left: 200px; } </style> </head> <body> <div id="progress"> <div id="filldiv"></div> <span id="percent">0</span> </div> </body> </html> <script src="common.js"></script> <script> window.onload = function(){ var fillDiv = $id("filldiv"); var per = $id("percent"); var timer = setInterval(function(){ //改变div的宽度 fillDiv.style.width = fillDiv.offsetWidth + 2 +"px"; fillDiv.style.backgroundColor = getColor(); //改变宽度的进度比例 per.innerHTML = parseInt(100*fillDiv.offsetWidth/200) + "%"; //判断fillDiv的宽度如果为200 就停止定时器 if(fillDiv.offsetWidth == 200){ clearInterval(timer) } },30) } </script>