php验证码类

<?php/* *$Captcha = new Captcha(); *//exit($Captcha->get_checkcode()); *$Captcha->set_checkimage_wh(60, 20); *$Captcha->out_checkimage(); */class Captcha {private $mCheckMode = 'number';//验证模式：'number': 数字 'add': 加法private $mCheckCodeNum = 4;//验证码位数private $mCheckCode = '';//产生的验证码private $mCheckResult = '';//加法运算后的答案private $mCheckImage = '';//验证码的图片private $mDisturbColor = '';//干扰像素private $mCheckImageWidth = '60';//验证码的图片宽度private $mCheckImageHeight = '20';//验证码的图片宽度/** * @brief 构造函数 生成验证码 */public function __construct($mode="number") {$this->mCheckMode = $mode;$this->create_checkcode();}/** * @brief 设置验证码图片的大小 * @param  $width 宽 * @param  $height 高 */public function set_checkimage_wh($width, $height)  {if ($width == '' || $height == '')return false;$this->mCheckImageWidth = $width;$this->mCheckImageHeight = $height;return true;}/** * @brief 设置验证码位数 * @param  $num 位数 */public function set_checkcode_num($num) {if ($num == '')return false;$this->mCheckCodeNum = $num;return true;}/** * @brief 取得验证码 */public function get_checkcode() {return $this->mCheckCode;}/** * @brief 取得验证运算结果 */public function get_checkresult() {return $this->mCheckResult;}/** * @brief 输出验证码图片 */public function out_checkimage() {$this->out_fileheader();$this->create_image();$this->set_disturb_color();$this->write_checkcode_to_image();imagepng($this->mCheckImage);imagedestroy($this->mCheckImage);}/** * @brief 输出头 */private function out_fileheader() {header ("Content-type: image/png");}/** * @brief 产生验证码 */private function create_checkcode() {if($this->mCheckMode == 'number') {$this->mCheckCode = strtoupper(substr(md5(rand()), 0, $this->mCheckCodeNum));} else {$num1 = rand(10, 49);$num2 = rand(10, 49);$this->mCheckResult = $num1 + $num2;$this->mCheckCode = $num1 .'+'. $num2 .'=';$this->set_checkcode_num(strlen($this->mCheckCode));}return $this->mCheckCode;}/** * @brief 产生验证码图片 */private function create_image() {$this->mCheckImage = @imagecreate ($this->mCheckImageWidth, $this->mCheckImageHeight);$bgcolor = imagecolorallocate ($this->mCheckImage, 245,245,245);//背景色$iborder = imagecolorallocate ($this->mCheckImage, 206,206,206);//边框色imagerectangle($this->mCheckImage, 0, 0, $this->mCheckImageWidth-1, $this->mCheckImageHeight-1, $iborder);return $this->mCheckImage;}/** * @brief 设置图片的干扰像素 */private function set_disturb_color() {for ($i = 0;$i <= 128;$i++) {$this->mDisturbColor = imagecolorallocate ($this->mCheckImage, rand(0, 255), rand(0, 255), rand(0, 255));imagesetpixel($this->mCheckImage, rand(2, 128), rand(2, 38), $this->mDisturbColor);}}/** * @brief 在验证码图片上逐个画上验证码 */private function write_checkcode_to_image() {for ($i = 0;$i <= $this->mCheckCodeNum;$i++) {$bg_color = imagecolorallocate ($this->mCheckImage, rand(0, 255), rand(0, 128), rand(0, 255));$x = floor($this->mCheckImageWidth / $this->mCheckCodeNum) * $i + 3;$y = rand(0, $this->mCheckImageHeight-15);imagechar ($this->mCheckImage, 5, $x, $y, $this->mCheckCode[$i], $bg_color);}}}