PHP中验证码类及使用方法

备注:将公共页面加入session_start();

<?php

session_start();

ini_set('display_errors', 'Off');

class CCheckCodeFile

{

       //验证码位数 www.2cto.com

       var $mCheckCodeNum  = 4;

       //产生的验证码

       var $mCheckCode   = '';

       //验证码的图片

       var $mCheckImage  = '';

       //干扰像素

       var $mDisturbColor  = '';

       //验证码的图片宽度

       var $mCheckImageWidth = '80';

       //验证码的图片宽度

       var $mCheckImageHeight  = '20';

       //输出头

       function OutFileHeader()

       {

              header ("Content-type: image/png");

       }

       //产生验证码

       function CreateCheckCode()

       {

              //$this->mCheckCode = strtoupper(substr(md5(rand()),0,$this->mCheckCodeNum));

              $this->mCheckCode = strtoupper(substr(rand(0,9999999999),0,$this->mCheckCodeNum));

              session_cache_expire(60);

              session_start();

              $_SESSION["code_str"] = $this->mCheckCode;

              return $this->mCheckCode;

       }

       //产生验证码图片

       function CreateImage()

       {

              $this->mCheckImage = @imagecreate ($this->mCheckImageWidth,$this->mCheckImageHeight);

              imagecolorallocate ($this->mCheckImage, 255, 255, 255);