code: public function setSign()
      {
          $this->buildData();
  
          if ($this->channel === Config::CMB_PAY) {
              $data = $this->retData['reqData'];
          } else {
              $data = $this->retData;
          }
          $values = ArrayUtil::removeKeys($data, ['sign']);
  
          $values = ArrayUtil::arraySort($values);
  
          $signStr = ArrayUtil::createLinkstring($values);
  
          $this->retData['sign'] = $this->makeSign($signStr);
      }
docs: 设置签名
  @author helei