php生成验证码图片程序_PHP教程

一款国外网站下载的php生成验证码图片代码，这个比较实用我们还举例说明了，有需要的朋友按上面保存成php就可以用了哦。

代码如下

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session_start(); if( isset($_POST['submit'])) {    if( $_SESSION['security_code'] == $_POST['security_code'] && !empty($_SESSION['security_code'] ) ) {   // Insert you code for processing the form here, e.g emailing the submission, entering it into a database.   echo 'Thank you. Your message said "'.$_POST['message'].'"';   unset($_SESSION['security_code']);    } else {   // Insert your code for showing an error message here   echo 'Sorry, you have provided an invalid security code';    } } else { ?>     Name:   Email:   Message:      Security Code:       } ?>

验证程序 CaptchaSecurityImages.php

代码如下

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session_start(); /* * File: CaptchaSecurityImages.php * Author: Simon Jarvis * Copyright: 2006 Simon Jarvis * Date: 03/08/06 * Updated: 07/02/07 * Requirements: PHP 4/5 with GD and FreeType libraries * Link: http://www.white-hat-web-design.co.uk/articles/php-captcha.php * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details: * http://www.gnu.org/licenses/gpl.html * */ class CaptchaSecurityImages {  var $font = 'monofont.ttf';  function generateCode($characters) {   /* list all possible characters, similar looking characters and vowels have been removed */   $possible = '23456789bcdfghjkmnpqrstvwxyz';   $code = '';   $i = 0;   while ($i    $code .= substr($possible, mt_rand(0, strlen($possible)-1), 1);    $i++;   }   return $code;  }  function CaptchaSecurityImages($width='120',$height='40',$characters='6') {   $code = $this->generateCode($characters);   /* font size will be 75% of the image height */   $font_size = $height * 0.75;   $image = @imagecreate($width, $height) or die('Cannot initialize new GD image stream');   /* set the colours */   $background_color = imagecolorallocate($image, 255, 255, 255);   $text_color = imagecolorallocate($image, 20, 40, 100);   $noise_color = imagecolorallocate($image, 100, 120, 180);   /* generate random dots in background */   for( $i=0; $i    imagefilledellipse($image, mt_rand(0,$width), mt_rand(0,$height), 1, 1, $noise_color);   }   /* generate random lines in background */   for( $i=0; $i    imageline($image, mt_rand(0,$width), mt_rand(0,$height), mt_rand(0,$width), mt_rand(0,$height), $noise_color);   }   /* create textbox and add text */   $textbox = imagettfbbox($font_size, 0, $this->font, $code) or die('Error in imagettfbbox function');   $x = ($width - $textbox[4])/2;   $y = ($height - $textbox[5])/2;   imagettftext($image, $font_size, 0, $x, $y, $text_color, $this->font , $code) or die('Error in imagettftext function');   /* output captcha image to browser */   header('Content-Type: image/jpeg');   imagejpeg($image);   imagedestroy($image);   $_SESSION['security_code'] = $code;  } } $width = isset($_GET['width']) ? $_GET['width'] : '120'; $height = isset($_GET['height']) ? $_GET['height'] : '40'; $characters = isset($_GET['characters']) && $_GET['characters'] > 1 ? $_GET['characters'] : '6'; $captcha = new CaptchaSecurityImages($width,$height,$characters); ?>

http://www.bkjia.com/PHPjc/629694.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/629694.htmlTechArticle一款国外网站下载的php生成验证码图片代码，这个比较实用我们还举例说明了，有需要的朋友按上面保存成php就可以用了哦。 代码如下 复制...