PHP image verification code class_PHP tutorial-PHP Tutorial-php.cn

[php]
/**
* Picture verification code class
* Generate image type verification code. The verification code contains numbers and capital letters. The md5 encrypted verification code is stored in the session
*
* How to use:
* $captcha = new Catpcha();
* $captcha->buildAndExportImage();
*
*Author: luojing
*Creation time: 2013-3-27 11:42:12 am
*/
class Captcha {

Private $width;//Width
Private $height; //Height
Private $codeNum;//Number of verification code characters
Private $image;//Verification code image resource
Private $sessionKey;//The name saved in the session
Private $captcha;//Verification code string
const charWidth = 10;//Single character width, changes according to the output character size

/**
* Create a verification code class and initialize related parameters
* @param $width image width
* @param $height Image height
* @param $codeNum The number of characters in the verification code
* @param $sessionKey The name saved in session
*/
Function __construct($width = 50, $height = 20, $codeNum = 4, $sessionKey = 'captcha') {
          $this->width = $width;
$this->height = $height;
$this->codeNum = $codeNum;
           $this->sessionKey = $sessionKey;

//Guarantee minimum height and width
If($height < 20) {
$this->height = 20;
         }
If($width < ($codeNum * self::charWidth + 10)) {//Reserve 5 pixel gaps on the left and right
$this->width = $codeNum * self::charWidth + 10;
         }
}

/**
* Construct and output the verification code image
*/
Public function buildAndExportImage() {
          $this->createImage();
$this->setDisturb();
          $this->setCaptcha();
          $this->exportImage();
}

/**
* Construct the image and set the background color
*/
Private function createImage() {
               //Create image                                                                                      $this->image = imagecreatetruecolor($this->width, $this->height);                                                             //Create background color
          $bg = imagecolorallocate($this->image, mt_rand(220, 255), mt_rand(220, 255), mt_rand(220, 255));
//Fill background color
imagefilledrectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $bg);
}

/**
*Set interference elements
*/
Private function setDisturb() {

//Set interference points
for($i = 0; $i < 150; $i++) {
            $color = imagecolorallocate($this->image, mt_rand(150, 200), mt_rand(150, 200), mt_rand(150, 200));
            imagesetpixel($this->image, mt_rand(5, $this->width - 10), mt_rand(5, $this->height - 3), $color);
        }

        //设置干扰线
        for($i = 0; $i < 10; $i++) {
            $color = imagecolorallocate($this->image, mt_rand(150, 220), mt_rand(150, 220), mt_rand(150, 220));
            imagearc($this->image, mt_rand(-10, $this->width), mt_rand(-10, $this->height), mt_rand(30, 300), mt_rand(20, 200), 55, 44, $color);
        }

        //创建边框色
        $border = imagecolorallocate($this->image, mt_rand(0, 50), mt_rand(0, 50), mt_rand(0, 50));
        //画边框
        imagerectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $border);
    }

    /**
* Generate and draw verification code
*/
    private function setCaptcha() {
        $str = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ';
        //生成验证码字符
        for($i = 0; $i < $this->codeNum; $i++) {
            $this->captcha .= $str{mt_rand(0, strlen($str) - 1)};
        }
        //绘制验证码
        for($i = 0; $i < strlen($this->captcha); $i++) {
            $color = imagecolorallocate($this->image, mt_rand(0, 200), mt_rand(0, 200), mt_rand(0, 200));
            $x = floor(($this->width - 10)/$this->codeNum);
            $x = $x*$i + floor(($x-self::charWidth)/2) + 5;
            $y = mt_rand(2, $this->height - 20);
            imagechar($this->image, 5, $x, $y, $this->captcha{$i}, $color);
        }
    }

    /*
     * 输出图像,验证码保存到session中
     */
    private function exportImage() {
        if(imagetypes() & IMG_GIF){
            header('Content-type:image/gif');
            imagegif($this->image);
        } else if(imagetypes() & IMG_PNG){
            header('Content-type:image/png');
            imagepng($this->iamge);
        } else if(imagetypes() & IMG_JPEG) {
            header('Content-type:image/jpeg');
            imagepng($this->iamge);
        } else {
            imagedestroy($this->image);
            die("Don't support image type!");
        }
        //将验证码信息保存到session中，md5加密
        if(!isset($_SESSION)){
            session_start();
        }
        $_SESSION[$this->sessionKey] = md5($this->captcha);

        imagedestroy($this->image);
    }

    function __destruct() {
        unset($this->width, $this->height, $this->codeNum,$this->captcha);
    }
}

/**
* Picture verification code class
* Generate image type verification code. The verification code contains numbers and capital letters. The md5 encrypted verification code is stored in the session
*
* How to use:
* $captcha = new Catpcha();
* $captcha->buildAndExportImage();
*
*Author: luojing
*Creation time: 2013-3-27 11:42:12 am
*/
class Captcha {

private $width;//Width
private $height; //Height
private $codeNum;//Number of verification code characters
private $image;//Verification code image resource
private $sessionKey;//The name saved in the session
private $captcha;//Verification code string
const charWidth = 10;//The width of a single character changes according to the output character size

/**
* Create a verification code class and initialize related parameters
* @param $width image width
* @param $height Image height
* @param $codeNum The number of characters in the verification code
* @param $sessionKey The name saved in session
*/
function __construct($width = 50, $height = 20, $codeNum = 4, $sessionKey = 'captcha') {
$this->width = $width;
$this->height = $height;
$this->codeNum = $codeNum;
$this->sessionKey = $sessionKey;

//Guarantee minimum height and width
if($height < 20) {
$this->height = 20;
}
if($width < ($codeNum * self::charWidth + 10)) {//Reserve 5 pixel gaps on the left and right
$this->width = $codeNum * self::charWidth + 10;
}
}

/**
* Construct and output verification code image
*/
public function buildAndExportImage() {
$this->createImage();
$this->setDisturb();
$this->setCaptcha();
$this->exportImage();
}

/**
* Construct the image and set the background color
*/
private function createImage() {
//Create image
$this->image = imagecreatetruecolor($this->width, $this->height);
//Create background color
$bg = imagecolorallocate($this->image, mt_rand(220, 255), mt_rand(220, 255), mt_rand(220, 255));
//Fill background color
imagefilledrectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $bg);
}

/**
* Set disturbing elements
*/
private function setDisturb() {

//Set interference point
for($i = 0; $i < 150; $i++) {
$color = imagecolorallocate($this->image, mt_rand(150, 200), mt_rand(150, 200), mt_rand(150, 200));
imagesetpixel($this->image, mt_rand(5, $this->width - 10), mt_rand(5, $this->height - 3), $color);
}

//Set interference line
for($i = 0; $i < 10; $i++) {
$color = imagecolorallocate($this->image, mt_rand(150, 220), mt_rand(150, 220), mt_rand(150, 220));
imagearc($this->image, mt_rand(-10, $this->width), mt_rand(-10, $this->height), mt_rand(30, 300), mt_rand(20, 200), 55 , 44, $color);
}

//Create border color
$border = imagecolorallocate($this->image, mt_rand(0, 50), mt_rand(0, 50), mt_rand(0, 50));
//Draw a border
imagerectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $border);
}

/**
* Generate and draw verification code
*/
private function setCaptcha() {
$str = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ';
//Generate verification code characters
for($i = 0; $i < $this->codeNum; $i++) {
$this->captcha .= $str{mt_rand(0, strlen($str) - 1)};
}
//Draw verification code
for($i = 0; $i < strlen($this->captcha); $i++) {
$color = imagecolorallocate($this->image, mt_rand(0, 200), mt_rand(0, 200), mt_rand(0, 200));
$x = floor(($this->width - 10)/$this->codeNum);
   $x = $x*$i + floor(($x-self::charWidth)/2) + 5;
   $y = mt_rand(2, $this->height - 20);
   imagechar($this->image, 5, $x, $y, $this->captcha{$i}, $color);
  }
}

/*
* 输出图像,验证码保存到session中
*/
private function exportImage() {
  if(imagetypes() & IMG_GIF){
   header('Content-type:image/gif');
   imagegif($this->image);
  } else if(imagetypes() & IMG_PNG){
   header('Content-type:image/png');
         imagepng($this->iamge);
  } else if(imagetypes() & IMG_JPEG) {
   header('Content-type:image/jpeg');
         imagepng($this->iamge);
  } else {
   imagedestroy($this->image);
   die("Don't support image type!");
  }
  //将验证码信息保存到session中，md5加密
  if(!isset($_SESSION)){
      session_start();
  }
  $_SESSION[$this->sessionKey] = md5($this->captcha);

        imagedestroy($this->image);
}

function __destruct() {
  unset($this->width, $this->height, $this->codeNum,$this->captcha);
}
}