php 验证码图片 程序

验证码图片 程序
/*
*文件名:class.safeCode.php
*类名:safeCode
*目的:生成web应用时所需的验证码图片
*当前版本:1.0.2
*作者:NoAngels
*联系方式:flare_1023@163.com QQ:82535599 MSN:atizu@hotmail.com
*开发时间:2008年06月20日
*最后更新:2008年06月21日
*更新内容:
*版本1.0.2
*1.更新了对linux主机支持,设置GDFONTPATH环境变量,
* putenv('GDFONTPATH=' . realpath('.'));
*2.对不支持antialias函数的时候避免采用此方法,避免低版本的GD库
*版本1.0.1
*1.更新了绘制指定类型图片,支持类型有:png,jpeg,gif.默认为png(此效果最佳)
*2.优化了部分代码
*/
class safeCode{
        function __construct(){
                #设置默认safe安全保护码
                $this->__safe = substr(md5(time()), 0 , 4);
        }
        function __destruct(){
                #释放资源
                unset($this->__img, $this->__canvasWidth, $this->__canvasHeight, $this->__codeLength, $this->__spacePerChar, $this->__code, $this->__safe, $this->__background, $this->__borderColor, $this->__colors, $this->__font, $this->__sessionName);
        }
        function setCanvas($, $){
                #设置画布宽度以及高度.有默认值
                $this->__canvasWidth = $width;
                $this->__canvasHeight = $height;
                $this->__img = imagecreatetruecolor($width, $height);               
                return;
        }
        function setSafe($char){
                #设置安全码,不调用系统会自己设置
                $this->__safe = $char;
                return;
        }
        function setCodeLength($num = 8){
                #设置验证码长度
                $this->__codeLength = $num;
        }       
        function setFont($fontName){
                #设置绘图时所用的字体,字体文件必须与类文件同目录
                $this->__font = $fontName;
                return;
        }
        function setBackground($arg1 = 255, $arg2 = 255, $arg3 = 255){
                #设置背景颜色
                $this->__background = imagecolorallocate($this->__img, $arg1, $arg2, $arg3);
                return;
        }
        function setBorderColor($arg1 = 128, $arg2 = 128, $arg3 = 128){
                #设置边框颜色
                $this->__borderColor = imagecolorallocate($this->__img, $arg1, $arg2, $arg3);
        }
        function setFontColor($arr){
                #设置绘图时所用颜色,参数为颜色集合数组
                foreach($arr as $color){
                        $this->__colors[] = imagecolorallocate($this->__img, $color[0], $color[1], $color[2]);
                }
                return;
        }       
        function setSession($sessionName = 'safeCode'){
                #设置session变量名,默认为$_SESSION['safeCode']
                $this->__sessionName = $sessionName;
                #$_SESSION[$sessionName] = $this->__code;
                return;
        }
        function display($type = 'png'){
                #显示图片,可指定显示类型,目前支持png(默认),jpeg,gif
                $this->__setSpacePerChar();
                imagefilledrectangle($this->__img, 1, 1, $this->__canvasWidth - 2, $this->__canvasHeight -2, $this->__background);
                imagerectangle($this->__img, 0, 0, $this->__canvasWidth - 1, $this->__canvasHeight - 1, $this->__borderColor);
                $this->__drawText($this->__colors, $this->__getCode(), $this->__font);
                #修正linux以及低版本的GD库问题
                if(function_exists(imageantialias)){
                   imageantialias($this->__img, true);
                }
                $_SESSION[$this->__sessionName] = $this->__code;
                switch ($type){
                        case 'png':
                                header('Content-type:image/png');                               
                                imagepng($this->__img);       
                        case 'jpeg':
                                header('Content-type:image/jpeg');                               
                                imagejpeg($this->__img, '' , 75);
                        case 'gif':
                                header('Content-type:image/gif');                               
                                imagegif($this->__img);       
                        default:
                                header('Content-type:image/png');                               
                                imagepng($this->__img);                                                                                                               
                }
                imagegif($this->__img);       
        }       
        private function __setSpacePerChar(){
                #私有函数,设置字符间隔
                $this->__spacePerChar = $this->__canvasWidth / $this->__codeLength;
                return;
        }
        private function __getCode(){
                #获取验证码
                $this->__code = substr(md5(time().$this->__safe), rand(0, 24), $this->__codeLength);
                return $this->__code;
        }
        private function  __drawText($colors, $code, $fontName){
                #开始绘图
                #设置GBFONTPATH为当前目录,不然linux环境下会报错
                putenv('GDFONTPATH=' . realpath('.'));
                for($i = 0; $i < strlen($code); $i++){
                        $color = $colors[$i % count($colors)];
                        imagettftext(
                                $this->__img,
                                24 + rand(0, 8),
                                -20 + rand(0, 40),
                                ($i + 0.3) * $this->__spacePerChar,
                                $this->__canvasHeight - 20 + rand(0, 20),
                                $color,
                                $fontName,
                                $code{$i}
                        );
                }
                #绘制随机实线
                for($i = 0; $i < 400; $i++){
                        $x1 = rand(5, $this->__canvasWidth - 5);
                        $y1 = rand(5, $this->__canvasHeight - 5);
                        $x2 = $x1 - 4 + rand(0, 8);
                        $y2 = $y1 - 4 + rand(0, 8);
                        imageline($this->__img, $x1, $y1, $x2, $y2, $this->__colors[rand(0, count($this->__colors) - 1)]);
                }
                return;
        }
        private $__img = NULL;
        private $__canvas;
        private $__canvas;
        private $__codeLength = 8;
        private $__spacePerChar = 0;
        private $__code = 12345678;
        private $__safe = 2008;
        private $__background = NULL;
        private $__borderColor = NULL;       
        private $__colors = array();
        private $__font = 'arial.ttf';
        private $__sessionName = '';
}
?>

使用方法.

#测试文件
include_once('class.safeCode.php');
session_start();
$safeCode = new safeCode;
$safeCode->setCanvas(200, 50);
$safeCode->setCodeLength(8);
$safeCode->setSafe('2008');#设置安全码,不设置有默认值,动态生成
$safeCode->setBackground();
$safeCode->setBorderColor();
$safeCode->setFont('arial.ttf');#设置字体.必须同目录,字体文件
$colors = array(array(128, 64, 192), array(192, 64, 128), array(108, 192, 64));
$safeCode->setFontColor($colors);
$safeCode->setSession();
$safeCode->display('jpeg');

?>