适用于自定义的验证码类！
<?php /* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ Class Image{ private $img; public $width = 85; public $height = 25; public $code; public $code_len = 4; public $code_str = "329832983DSDSKDSLKQWEWQ2lkfDSFSDjfdsfdsjwlkfj93290KFDSKJFDSOIDSLK"; public $bg_color = '#DCDCDC'; public $font_size = 16; public $font = 'font.ttf'; public $font_color = '#000000'; //创建验证码饿字符创 public function create_code(){ $code = ''; for( $i=0;$i<$this->code_len;$i++ ){ $code .= $this->code_str[mt_rand(0, strlen($this->code_str)-1)]; } return $this->code = $code; } //输出图像 public function getImage(){ $w = $this->width; $h = $this->height; $bg_color = $this->bg_color; $img = imagecreatetruecolor($w, $h); $bg_color = imagecolorallocate($img, hexdec(substr($bg_color, 1,2)), hexdec(substr($bg_color, 3,2)), hexdec(substr($bg_color, 5,2))); imagefill($img, 0, 0, $bg_color); $this->img = $img; $this->create_font(); $this->create_pix(); $this->show_code(); } //写入验证码 public function create_font(){ $this->create_code(); $color = $this->font_color; $font_color = imagecolorallocate($this->img, hexdec(substr($color,1,2)), hexdec(substr($color, 3,2)), hexdec(substr($color,5,2))); $x = $this->width/$this->code_len; for( $i=0;$i<$this->code_len;$i++ ){ $txt_color = imagecolorallocate($this->img, mt_rand(0,100), mt_rand(0, 150), mt_rand(0, 200)); imagettftext($this->img, $this->font_size, mt_rand(-30, 30), $x*$i+mt_rand(3, 6), mt_rand($this->height/1.2, $this->height), $txt_color, $this->font , $this->code[$i]); //imagestring($this->img, $this->font_size, $x*$i+mt_rand(3, 6),mt_rand(0, $this->height/4) , $this->code[$i], $font_color); } $this->font_color = $font_color; } //画干扰线 public function create_pix(){ $pix_color= $this->font_color; for($i=0;$i<100;$i++){ imagesetpixel($this->img, mt_rand(0, $this->width),mt_rand(0, $this->height), $pix_color); } for($j=0;$j<4;$j++){ imagesetthickness($this->img, mt_rand(1, 2)); imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $pix_color); } } //得到验证码 public function getCode(){ return strtoupper($this->code); } //输出验证码 private function show_code(){ header("Content-type:image/png"); imagepng($this->img); imagedestroy($this->img); } }
我们再来看一例代码：
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
<?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(); * * 作 者: luojing * 创建时间: 2013-3-27 上午11:42:12 */ class 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 = 20, $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() { $str = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ'; //生成验证码字符 for($i = 0; $i < $this->codeNum; $i++) { $this->captcha .= $str{mt_rand(0, strlen($str) - 1)}; } //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}, $color); } } /* * 输出图像,验证码保存到session中 */ private function exportImage() { if(imagetypes() & IMG_GIF){ header('Content-type:image/gif'); imagegif($this->image); } else if(imagetypes() & IMG_PNG){ header('Content-type:image/png'); imagepng($this->iamge); } else if(imagetypes() & IMG_JPEG) { header('Content-type:image/jpeg'); imagepng($this->iamge); } else { imagedestroy($this->image); die("Don't support image type!"); } //将验证码信息保存到session中，md5加密 if(!isset($_SESSION)){ session_start(); } $_SESSION[$this->sessionKey] = md5($this->captcha); imagedestroy($this->image); } function __destruct() { unset($this->width, $this->height, $this->codeNum,$this->captcha); } }
例三：