一个不错的php验证码的类
类的代码：
1 <?php 2 3 class Captcha 4 { 5 private $width; 6 private $height; 7 private $codeNum; 8 private $code; 9 private $im; 10 11 function __construct($width=80, $height=20, $codeNum=4) 12 { 13 $this->width = $width; 14 $this->height = $height; 15 $this->codeNum = $codeNum; 16 } 17 18 function showImg() 19 { 20 //创建图片 21 $this->createImg(); 22 //设置干扰元素 23 $this->setDisturb(); 24 //设置验证码 25 $this->setCaptcha(); 26 //输出图片 27 $this->outputImg(); 28 } 29 //http://www.cnblogs.com/sosoft/ 30 function getCaptcha() 31 { 32 return $this->code; 33 } 34 35 private function createImg() 36 { 37 $this->im = imagecreatetruecolor($this->width, $this->height); 38 $bgColor = imagecolorallocate($this->im, 0, 0, 0); 39 imagefill($this->im, 0, 0, $bgColor); 40 } 41 42 private function setDisturb() 43 { 44 $area = ($this->width * $this->height) / 20; 45 $disturbNum = ($area > 250) ? 250 : $area; 46 //加入点干扰 47 for ($i = 0; $i < $disturbNum; $i++) { 48 $color = imagecolorallocate($this->im, rand(0, 255), rand(0, 255), rand(0, 255)); 49 imagesetpixel($this->im, rand(1, $this->width - 2), rand(1, $this->height - 2), $color); 50 } 51 //加入弧线 52 for ($i = 0; $i <= 5; $i++) { 53 $color = imagecolorallocate($this->im, rand(128, 255), rand(125, 255), rand(100, 255)); 54 imagearc($this->im, rand(0, $this->width), rand(0, $this->height), rand(30, 300), rand(20, 200), 50, 30, $color); 55 } 56 } 57 58 private function createCode() 59 { 60 $str = "23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKMNPQRSTUVWXYZ"; 61 62 for ($i = 0; $i < $this->codeNum; $i++) { 63 $this->code .= $str{rand(0, strlen($str) - 1)}; 64 } 65 } 66 67 private function setCaptcha() 68 { 69 $this->createCode(); 70 71 for ($i = 0; $i < $this->codeNum; $i++) { 72 $color = imagecolorallocate($this->im, rand(50, 250), rand(100, 250), rand(128, 250)); 73 $size = rand(floor($this->height / 5), floor($this->height / 3)); 74 $x = floor($this->width / $this->codeNum) * $i + 5; 75 $y = rand(0, $this->height - 20); 76 imagechar($this->im, $size, $x, $y, $this->code{$i}, $color); 77 } 78 } 79 80 private function outputImg() 81 { 82 if (imagetypes() & IMG_JPG) { 83 header('Content-type:image/jpeg'); 84 imagejpeg($this->im); 85 } elseif (imagetypes() & IMG_GIF) { 86 header('Content-type: image/gif'); 87 imagegif($this->im); 88 } elseif (imagetype() & IMG_PNG) { 89 header('Content-type: image/png'); 90 imagepng($this->im); 91 } else { 92 die("Don't support image type!"); 93 } 94 } 95 96 }
?>
使用的一个例子：
<?php require_once 'captcha.class.php'; $captcha = new Captcha(80,30,4); $captcha->showImg(); ?>
