<?php session_start(); header("content-type: image/gif"); class securitycode { private $codes = ''; function __construct() { $code = '0-1-2-3-4-5-6-7-8-9-a-b-c-d-e-f-g-h-i-j-k-l-m-n-o-p-q-r-s-t-u-v-w-x-y-z'; $codearray = explode('-',$code); shuffle($codearray); $this->codes = implode('',array_slice($codearray,0,4)); } public function createimg() { $_session['check_pic'] = $this->codes; $img = imagecreate(70,25); imagecolorallocate($img,222,222,222); $testcolor1 = imagecolorallocate($img,255,0,0); $testcolor2 = imagecolorallocate($img,51,51,51); $testcolor3 = imagecolorallocate($img,0,0,255); $testcolor4 = imagecolorallocate($img,255,0,255); for ($i = 0; $i < 4; $i++) { imagestring($img,rand(5,6),8 + $i * 15,rand(2,8),$this->codes[$i],rand(1,4)); } imagegif($img); } } $code = new securitycode(); $code->createimg(); $code = null; ?>
封装成类之后，加入了构造函数，使用起来也方便些。你也可以继续完善下这个验证码类，比如加入析构函数，如何更节省内存等等。