Thinkphp3.2实用篇之计算型验证码示例

public function entry_add($id = '') {    $this->length='3';    // 图片宽(px)    $this->imageW || $this->imageW = $this->length*$this->fontSize*1.5 + $this->length*$this->fontSize/2;     // 图片高(px)    $this->imageH || $this->imageH = $this->fontSize * 2.5;    // 建立一幅 $this->imageW x $this->imageH 的图像    $this->_image = imagecreate($this->imageW, $this->imageH);     // 设置背景       imagecolorallocate($this->_image, $this->bg[0], $this->bg[1], $this->bg[2]);     // 验证码字体随机颜色    $this->_color = imagecolorallocate($this->_image, mt_rand(1,150), mt_rand(1,150), mt_rand(1,150));    // 验证码使用随机字体    $ttfPath = dirname(__FILE__) . '/Verify/' . ($this->useZh ? 'zhttfs' : 'ttfs') . '/';    if(empty($this->fontttf)){      $dir = dir($ttfPath);      $ttfs = array();          while (false !== ($file = $dir->read())) {        if($file[0] != '.' && substr($file, -4) == '.ttf') {          $ttfs[] = $file;        }      }      $dir->close();      $this->fontttf = $ttfs[array_rand($ttfs)];    }     $this->fontttf = $ttfPath . $this->fontttf;        if($this->useImgBg) {      $this->_background();    }        if ($this->useNoise) {      // 绘杂点      $this->_writeNoise();    }    if ($this->useCurve) {      // 绘干扰线      $this->_writeCurve();    }        // 绘验证码    $code = array(); // 验证码    $symbol=array('+','-');    $codeNX = 0; // 验证码第N个字符的左边距    $now_symbol=$symbol[rand(0,1)];    for ($i = 0; $i<$this->length; $i++) {      if($i==1){        $code[$i] = $now_symbol;        $codeNX += mt_rand($this->fontSize*1.2, $this->fontSize*1.6);        imagettftext($this->_image, $this->fontSize,0, $codeNX, $this->fontSize*1.6, $this->_color, $ttfPath.'2.ttf', $code[$i]);      }      else{        $code[$i] = $this->codeSet[mt_rand(0, strlen($this->codeSet)-1)];        $codeNX += mt_rand($this->fontSize*1.2, $this->fontSize*1.6);        imagettftext($this->_image, $this->fontSize, mt_rand(-40, 40), $codeNX, $this->fontSize*1.6, $this->_color, $this->fontttf, $code[$i]);      }     }        // 保存验证码    $key    =  $this->authcode($this->seKey);    $str=implode('', $code);    eval("/$re=$str;");    $code    =  $this->authcode($re);    $secode   =  array();    $secode['verify_code'] = $code; // 把校验码保存到session    $secode['verify_time'] = NOW_TIME; // 验证码创建时间    session($key.$id, $secode);                header('Cache-Control: private, max-age=0, no-store, no-cache, must-revalidate');    header('Cache-Control: post-check=0, pre-check=0', false);        header('Pragma: no-cache');    header("content-type: image/png");    // 输出图像    imagepng($this->_image);    imagedestroy($this->_image);  }

public function check_add($code, $id = '') {    $key = $this->authcode($this->seKey).$id;    // 验证码不能为空    $secode = session($key);    if($code===false || empty($secode)) {      return false;    }    //验证码是否是数字    if(!is_numeric($code)) {      return false;    }    // session 过期    if(NOW_TIME - $secode['verify_time'] > $this->expire) {      session($key, null);      return false;    }    if($this->authcode($code) == $secode['verify_code']) {      $this->reset && session($key, null);      return true;    }    return false;  }

Public function verify(){    import('ORG.Util.Verify');    $Verify = new Verify();    $Verify->useNoise = true;    $Verify->codeSet = '0123456789';    $Verify->useCurve = false;    $Verify->entry_add();  }

 if (!check_verify($verify,'','add')) {      $this->error('验证码错误！');      return;    }

 // 检测输入的验证码是否正确，$code为用户输入的验证码字符串function check_verify($code, $id = '',$type=''){  import('ORG.Util.Verify');  $verify = new Verify();  if($type='add'){    return $verify->check_add($code, $id);  }  else{    return $verify->check($code, $id);  }}