设计一个验证码类，在需要的时候可以随时调用

验证码类，保存为ValidateCode.class.php

 1 <?php 2 //验证码类 3 session_start(); 4 class ValidateCode { 5  PRivate $charset = 'abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ23456789';//随机因子 6  private $code;//验证码 7  private $codelen = 4;//验证码长度 8  private $width = 130;//宽度 9  private $height = 50;//高度10  private $img;//图形资源句柄11  private $font;//指定的字体12  private $fontsize = 20;//指定字体大小13  private $fontcolor;//指定字体颜色14  //构造方法初始化15  public function __construct() {16   $this->font = './latha.ttf';//注意字体路径要写对，否则显示不了图片17  }18  //生成随机码19  private function createCode() {20   $_len = strlen($this->charset)-1;21   for ($i=0;$i<$this->codelen;$i++) {22    $this->code .= $this->charset[mt_rand(0,$_len)];23   }24  }25  //生成背景26  private function createBg() {27   $this->img = imagecreatetruecolor($this->width, $this->height);28   $color = imagecolorallocate($this->img, mt_rand(157,255), mt_rand(157,255), mt_rand(157,255));29   imagefilledrectangle($this->img,0,$this->height,$this->width,0,$color);30  }31  //生成文字32  private function createFont() {33   $_x = $this->width / $this->codelen;34   for ($i=0;$i<$this->codelen;$i++) {35    $this->fontcolor = imagecolorallocate($this->img,mt_rand(0,156),mt_rand(0,156),mt_rand(0,156));36    imagettftext($this->img,$this->fontsize,mt_rand(-30,30),$_x*$i+mt_rand(1,5),$this->height / 1.4,$this->fontcolor,$this->font,$this->code[$i]);37   }38  }39  //生成线条、雪花40  private function createLine() {41   //线条42   for ($i=0;$i<6;$i++) {43    $color = imagecolorallocate($this->img,mt_rand(0,156),mt_rand(0,156),mt_rand(0,156));44    imageline($this->img,mt_rand(0,$this->width),mt_rand(0,$this->height),mt_rand(0,$this->width),mt_rand(0,$this->height),$color);45   }46   //雪花47   for ($i=0;$i<100;$i++) {48    $color = imagecolorallocate($this->img,mt_rand(200,255),mt_rand(200,255),mt_rand(200,255));49    imagestring($this->img,mt_rand(1,5),mt_rand(0,$this->width),mt_rand(0,$this->height),'*',$color);50   }51  }52  //输出53  private function outPut() {54  header('Content-type:image/png');55   imagepng($this->img);56   imagedestroy($this->img);57  }58  //对外生成59  public function doimg() {60   $this->createBg();61   $this->createCode();62   $this->createLine();63   $this->createFont();64   $this->outPut();65  }66  //获取验证码67  public function getCode() {68   return strtolower($this->code);69  }70 }

注意：第16行中，要修改字体的路径，否则字体图片无法显示

实现，保存为captcha.php

1 session_start();2 require './ValidateCode.class.php';  //先把类包含进来，实际路径根据实际情况进行修改。3 $_vc = new ValidateCode();  //实例化一个对象4 $_vc->doimg();  5 $_SESSION['authnum_session'] = $_vc->getCode();//验证码保存到SESSION中

页面使用

<img  title="点击刷新" src="./captcha.php" align="absbottom" onclick="this.src='captcha.php?'+Math.random();"></img>

转载自：一个漂亮的php验证码类(分享)