php生成图片验证码

来源：互联网发布：域名投资编辑：程序博客网时间：2024/06/05 05:02

<?php/* * 图片验证码类 * 生成图片类型验证码，验证码包含数字和大写字母，session中存放md5加密后的验证码 *  * 使用方法： * $captcha = new Catpcha(); * $captcha->buildAndExportImage();

 * */class Lib_Captcha {        private $width;//宽度    private $height; //高度    private $codeNum;//验证码字符数量    private $image;//验证码图像资源    private $sessionKey;//session中保存的名字    private $captcha;//验证码字符串    const charWidth = 10;//单个字符宽度,根据输出字符大小而变        /**     * 创建验证码类，初始化相关参数     * @param  $width 图片宽度     * @param  $height 图片高度     * @param  $codeNum 验证码字符数量     * @param  $sessionKey session中保存的名字     */    function __construct($width = 50, $height = 30, $codeNum = 4, $sessionKey = 'captcha') {        $this->width = $width;        $this->height = $height;        $this->codeNum = $codeNum;        $this->sessionKey = $sessionKey;                //保证最小高度和宽度        if($height < 20) {            $this->height = 20;        }        if($width < ($codeNum * self::charWidth + 10)) {//左右各保留5像素空隙            $this->width = $codeNum * self::charWidth + 10;        }    }        /**     * 构造并输出验证码图片     */    public  function buildAndExportImage() {        $this->createImage();        $this->setDisturb();                $this->setCaptcha();                $this->exportImage();    }        /**     * 构造图像，设置底色     */    private function createImage() {        //创建图像        $this->image = imagecreatetruecolor($this->width, $this->height);          //创建背景色        $bg = imagecolorallocate($this->image, mt_rand(220, 255), mt_rand(220, 255), mt_rand(220, 255));          //填充背景色        imagefilledrectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $bg);    }        /**     * 设置干扰元素     */    private function setDisturb() {                //设置干扰点        for($i = 0; $i < 150; $i++) {            $color = imagecolorallocate($this->image, mt_rand(150, 200),  mt_rand(150, 200),  mt_rand(150, 200));            imagesetpixel($this->image, mt_rand(5, $this->width - 10), mt_rand(5, $this->height - 3), $color);        }                //设置干扰线        for($i = 0; $i < 10; $i++) {            $color = imagecolorallocate($this->image, mt_rand(150, 220), mt_rand(150, 220), mt_rand(150, 220));            imagearc($this->image, mt_rand(-10, $this->width), mt_rand(-10, $this->height), mt_rand(30, 300), mt_rand(20, 200), 55, 44, $color);        }                //创建边框色        $border = imagecolorallocate($this->image, mt_rand(0, 50), mt_rand(0, 50), mt_rand(0, 50));        //画边框        imagerectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $border);    }        /**     * 产生并绘制验证码     */    private function setCaptcha() {         //复杂验证码      $code = '';      $box  = 'qwrtyuiopasdfghjklzx012345789cvbnmQAZWSXEDCRFVTGBYHNUJMKIOLP0123456789';      for($i=0;$i<$this->codeNum;$i++) $code .= $box[rand(0,69)];      $this->captcha = $code;            /*        $str = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ';        //生成验证码字符        for($i = 0; $i < $this->codeNum; $i++) {            $this->captcha .= $str{mt_rand(0, strlen($str) - 1)};        }*/        //session_start();        //$_SESSION['captcha'] = $this->captcha;        //链接REDIS        $Redis = Lib_Redis::getInstance();        if($Redis->redis == false) return;        //获取redis前缀键值        $prefix = Yaf_Registry::get('Config')->REDIS_DB_PREFIX;        $Redis->redis->set($prefix.session_id(),$this->captcha,300);        //绘制验证码        for($i = 0; $i < strlen($this->captcha); $i++) {            $color = imagecolorallocate($this->image, mt_rand(0, 200), mt_rand(0, 200), mt_rand(0, 200));            $x = floor(($this->width - 10)/$this->codeNum);            $x = $x*$i + floor(($x-self::charWidth)/2) + 5;            $y = mt_rand(2, $this->height - 20);            imagechar($this->image, 5, $x, $y, $this->captcha{$i}, $color);        }    }    public function getCaptcha()    {        return $this->captcha;    }        /*     * 输出图像,验证码保存到session中     */    private function exportImage() {                //将验证码信息保存到session中，md5加密        if(!isset($_SESSION)){            session_start();        }         //$_SESSION['captcha']=$this->getCaptcha();        if(imagetypes() & IMG_GIF){            header('Content-type:image/gif');            imagegif($this->image);        } else if(imagetypes() & IMG_PNG){            header('Content-type:image/png');              imagepng($this->image);        } else if(imagetypes() & IMG_JPEG) {            header('Content-type:image/jpeg');              imagepng($this->image);        } else {            imagedestroy($this->image);            die("Don't support image type!");        }                imagedestroy($this->image);      }        function __destruct() {        unset($this->width, $this->height, $this->codeNum,$this->captcha);    }}

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