code: protected function checkDataParam()
      {
          $openId = $this->openid;
          $transNo = $this->trans_no;
          $checkName = $this->check_name;
          $realName = $this->payer_real_name;
          $amount = $this->amount;
          $clientIp = $this->client_ip;
  
          if (empty($openId)) {
              throw new PayException('商户appid下，某用户的openid 必须传入');
          }
  
          if (empty($transNo)) {
              throw new PayException('商户订单号，需保持唯一性');
          }
  
          if ($checkName !== 'NO_CHECK' && empty($realName)) {
              throw new PayException('请传入收款人真实姓名');
          }
  
          // 微信使用的单位位分.此处进行转化
          $this->amount = bcmul($amount, 100, 0);
          if (empty($amount) || $amount < 0) {
              throw new PayException('转账金额错误');
          }
  
          if (empty($clientIp)) {
              $this->client_ip = isset($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : '127.0.0.1';
          }
      }
docs: 检查相关参数是否设置
  @author helei