花了一个上午的时间，终于提取出来了，效果演示：
下面是代码：
<?php
session_start();
class seccode {
var $code ; // 验证码
var $type = 0; // 只能是0
var $width = 70; // 图像宽度
var $height = 21; // 图像高度
var $background = 1; // 1背景随机变换，0不变换
var $adulterate = 1; // 1有干扰线，0没有干扰线
var $ttf = 1; // 只能是1
var $angle = 0; // 1角度随机旋转 0不旋转
var $color = 1; // 1字体颜色随机 0不随机
var $size = 0; // 1字体大小随机 0不随机
var $shadow = 1; // 1文字有阴影 0没有阴影
var $animator = 0; //只能是0
var $fontpath = ''; // 字体路径
var $fontcolor;
var $im;
function display() {
$this->code = $this->gencode();
$_SESSION['vdc'] = $this->code;
$this->width = $this->width >= 0 && $this->width <= 200 ? $this->width : 150;
$this->height = $this->height >= 0 && $this->height <= 80 ? $this->height : 60;
if($this->type < 2 && function_exists('imagecreate') && function_exists('imagecolorset') && function_exists('imagecopyresized') &&
function_exists('imagecolorallocate') && function_exists('imagechar') && function_exists('imagecolorsforindex') &&
function_exists('imageline') && function_exists('imagecreatefromstring') && (function_exists('imagegif') || function_exists('imagepng') || function_exists('imagejpeg'))) {
$this->image();
}
}
function gencode() {
$arr=array('3','4','5','6','7','8','9','Q','W','E','R','T','Y','U','P','L','K','J','H','G','F','D','S','A','X','C','V','B','N','M');//声明一个数组，中文验证码的来源
$ss1=rand(0,29);
$ss2=rand(0,29);
$ss3=rand(0,29);
$ss4=rand(0,29);
$string=$arr[$ss1].$arr[$ss2].$arr[$ss3].$arr[$ss4];//根据随机数，输出四个随机数组元素，组成字符串
return $string;
}
function fileext($filename) {
return trim(substr(strrchr($filename, '.'), 1, 10));
}
function image() {
$bgcontent = $this->background();
$this->im = imagecreatefromstring($bgcontent);
$this->adulterate && $this->adulterate();
$this->ttf && function_exists('imagettftext') || $this->type == 1 ? $this->ttffont() : $this->giffont();
if(function_exists('imagepng')) {
header('Content-type: image/png');
imagepng($this->im);
} else {
header('Content-type: image/jpeg');
imagejpeg($this->im, '', 100);
}
imagedestroy($this->im);
}
function background() {
$this->im = imagecreatetruecolor($this->width, $this->height);
$backgroundcolor = imagecolorallocate($this->im, 255, 255, 255);
$backgrounds = $c = array();
if($this->background && function_exists('imagecreatefromjpeg') && function_exists('imagecolorat') && function_exists('imagecopymerge') &&
function_exists('imagesetpixel') && function_exists('imageSX') && function_exists('imageSY')) {
if($handle = @opendir($this->datapath.'background/')) {
while($bgfile = @readdir($handle)) {
if(preg_match('/\.jpg$/i', $bgfile)) {
$backgrounds[] = $this->datapath.'background/'.$bgfile;
}
}
@closedir($handle);
}
if($backgrounds) {
$imwm = imagecreatefromjpeg($backgrounds[array_rand($backgrounds)]);
$colorindex = imagecolorat($imwm, 0, 0);
$this->c = imagecolorsforindex($imwm, $colorindex);
$colorindex = imagecolorat($imwm, 1, 0);
imagesetpixel($imwm, 0, 0, $colorindex);
$c[0] = $c['red'];$c[1] = $c['green'];$c[2] = $c['blue'];
imagecopymerge($this->im, $imwm, 0, 0, mt_rand(0, 200 - $this->width), mt_rand(0, 80 - $this->height), imageSX($imwm), imageSY($imwm), 100);
imagedestroy($imwm);
}
}
if(!$this->background || !$backgrounds) {
for($i = 0;$i < 3;$i++) {
$start[$i] = mt_rand(200, 255);$end[$i] = mt_rand(100, 150);$step[$i] = ($end[$i] - $start[$i]) / $this->width;$c[$i] = $start[$i];
}
for($i = 0;$i < $this->width;$i++) {
$color = imagecolorallocate($this->im, $c[0], $c[1], $c[2]);
imageline($this->im, $i, 0, $i-(isset($angle) ? $angle : 0), $this->height, $color);
$c[0] += $step[0];$c[1] += $step[1];$c[2] += $step[2];
}
$c[0] -= 20;$c[1] -= 20;$c[2] -= 20;
}
ob_start();
if(function_exists('imagepng')) {
imagepng($this->im);
} else {
imagejpeg($this->im, '', 100);
}
imagedestroy($this->im);
$bgcontent = ob_get_contents();
ob_end_clean();
$this->fontcolor = $c;
return $bgcontent;
}
function adulterate() {
$linenums = $this->height / 10;
for($i=0; $i <= $linenums; $i++) {
$color = $this->color ? imagecolorallocate($this->im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255)) : imagecolorallocate($this->im, $this->fontcolor[0], $this->fontcolor[1], $this->fontcolor[2]);
$x = mt_rand(0, $this->width);
$y = mt_rand(0, $this->height);
if(mt_rand(0, 1)) {
imagearc($this->im, $x, $y, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, 360), mt_rand(0, 360), $color);
} else {
$linemaxlong = isset($linemaxlong) ? $linemaxlong : 0;
$linex = isset($linex) ? $linex : 0;
$liney = isset($liney) ? $liney : 0;
imageline($this->im, $x, $y, $linex + mt_rand(0, $linemaxlong), $liney + mt_rand(0, mt_rand($this->height, $this->width)), $color);
}
}
}
function ttffont() {
$seccode = $this->code;
$charset = isset($GLOBALS['charset']) ? $GLOBALS['charset'] : '';
$seccoderoot = $this->fontpath;
$dirs = opendir($seccoderoot);
$seccodettf = array();
while($entry = readdir($dirs)) {
if($entry != '.' && $entry != '..' && in_array(strtolower($this->fileext($entry)), array('ttf', 'ttc'))) {
$seccodettf[] = $entry;
}
}
$seccodelength = 4;
$widthtotal = 0;
for($i = 0; $i < $seccodelength; $i++) {
$font[$i]['font'] = $seccoderoot.$seccodettf[array_rand($seccodettf)];
$font[$i]['angle'] = $this->angle ? mt_rand(-30, 30) : 0;
$font[$i]['size'] = $this->type ? $this->width / 7 : $this->width / 6;
$this->size && $font[$i]['size'] = mt_rand($font[$i]['size'] - $this->width / 40, $font[$i]['size'] + $this->width / 20);
$box = imagettfbbox($font[$i]['size'], 0, $font[$i]['font'], $seccode[$i]);
$font[$i]['zheight'] = max($box[1], $box[3]) - min($box[5], $box[7]);
$box = imagettfbbox($font[$i]['size'], $font[$i]['angle'], $font[$i]['font'], $seccode[$i]);
$font[$i]['height'] = max($box[1], $box[3]) - min($box[5], $box[7]);
$font[$i]['hd'] = $font[$i]['height'] - $font[$i]['zheight'];
$font[$i]['width'] = (max($box[2], $box[4]) - min($box[0], $box[6])) + mt_rand(0, $this->width / 8);
$font[$i]['width'] = $font[$i]['width'] > $this->width / $seccodelength ? $this->width / $seccodelength : $font[$i]['width'];
$widthtotal += $font[$i]['width'];
}
$x = mt_rand($font[0]['angle'] > 0 ? cos(deg2rad(90 - $font[0]['angle'])) * $font[0]['zheight'] : 1, $this->width - $widthtotal);
!$this->color && $text_color = imagecolorallocate($this->im, $this->fontcolor[0], $this->fontcolor[1], $this->fontcolor[2]);
for($i = 0; $i < $seccodelength; $i++) {
if($this->color) {
$this->fontcolor = array(mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));
$this->shadow && $text_shadowcolor = imagecolorallocate($this->im, 255 - $this->fontcolor[0], 255 - $this->fontcolor[1], 255 - $this->fontcolor[2]);
$text_color = imagecolorallocate($this->im, $this->fontcolor[0], $this->fontcolor[1], $this->fontcolor[2]);
} elseif($this->shadow) {
$text_shadowcolor = imagecolorallocate($this->im, 255 - $this->fontcolor[0], 255 - $this->fontcolor[1], 255 - $this->fontcolor[2]);
}
$y = $font[0]['angle'] > 0 ? mt_rand($font[$i]['height'], $this->height) : mt_rand($font[$i]['height'] - $font[$i]['hd'], $this->height - $font[$i]['hd']);
$this->shadow && imagettftext($this->im, $font[$i]['size'], $font[$i]['angle'], $x + 1, $y + 1, $text_shadowcolor, $font[$i]['font'], $seccode[$i]);
imagettftext($this->im, $font[$i]['size'], $font[$i]['angle'], $x, $y, $text_color, $font[$i]['font'], $seccode[$i]);
$x += $font[$i]['width'];
}
}
}
$code = new seccode();
$code->width = 80; // 宽度
$code->height = 25; // 高度
$code->background = 1; // 1背景随机变换，0不变换
$code->adulterate = 1; // 1有干扰线，0没有干扰线
$code->angle = 0; // 1旋转 0不旋转
$code->color = 1; // 1字体颜色随机 0不随机
$code->size = 1; // 1字体大小随机 0不随机
$code->shadow = 1; // 1文字有阴影 0没有阴影
$code->fontpath = $_SERVER['DOCUMENT_ROOT'].'\\vdtest\\'; // 字体路径
$code->display();
?>
完全就是从discuz中复制出来的，然后把一些没必要的代码都删除了的，本地预览和在网上预览的时候注意要更改那个字体路径的就行，路径中可以放多个ttf字体文件，这样就能随机字体也不同了。
在我要把我提取出来的整合到niunan.org上时，发现在本地预览出错，晕，后来查了下，原来不是验证码的问题，是我本机的WAMP升级了，本机现在是PHP5.3了，但是空间上的还是PHP5.2.9，在判断是否有URL参数的时候我是写
if($_GET["caid])...
但是在PHP5.3中这样写就报错了，应该写成：
if(!empty($_GET['caid']))....
唉。。还得找时间再改改哦。。。
