flex checkCode验证码

package com.wks.util { ?public class CheckCode ?{ ??public function CheckCode() ??{ ??} ?? ??/*获取验证码? 传入空间参数id?? ??*调用方法： ??*???<s:Label id="asd" width="80" height="20" color="#377CD0" text="{getcheckCode(asd)}" ??fontFamily="Georgia" fontSize="20" digitWidth="tabular"/> ??*???<mx:LinkButton label="看不清楚？" click="{asd.text=getcheckCode(asd)}"/> ??*/ ??public function getcheckCode(obj:Object):String ??{ ???var ran:Number;????//获取随机数 ???var number:Number;???//得到单个数字 ???var code:String;???//获得通过number转化的字符 ???var checkCode:String = "";?//得到的随机数 ??? ???//生成四位随机数 ???for(var i:int=0;i<4;i++){ ????ran = Math.random(); ????number = Math.round(ran*10000); ???? ????if(number % 3 == 0) ????{?//"A"--"Z"的ASCII码为65-90 "a"--"z" 97--122 ?????// 二次判断是 取数字或是 大写字母 ?????if(number % 2 == 0){ ??????code = String.fromCharCode(48 + (number % 10)); ?????}else { ??????code = String.fromCharCode(65 + (number % 26)); ?????} ????}else if(number % 3 == 1) ????{ ?????// 二次判断是 取数字或是 小写字母 ?????if(number % 2 == 0){ ??????code = String.fromCharCode(48 + (number % 10)); ?????}else { ??????code = String.fromCharCode(97 + (number % 26)); ?????} ????}else { ?????//对3取余数为2时 进入? ?????if(number % 2 == 0){ ??????code = String.fromCharCode(48 + (number % 10)); ?????}else { ??????code = String.fromCharCode(97 + (number % 26)); ?????} ????} ???? ????checkCode += code; ???? ???} ??? ???//绘制躁点 ???obj.graphics.clear(); ???var c:int = checkCode.length * 25; ???for(var j:int=0; j<c;j++) ???{ ????var x:int = Math.random() * obj.width; ????var y:int = Math.random() * obj.height; ????obj.graphics.lineStyle(1,0x7C929D); ????obj.graphics.drawRect(x,y,.5,.5); ???} ???return checkCode; ??} ?} }