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 "\$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);
  }
}