code: protected function checkDataParam()
      {
          $transNo = $this->trans_no;
          $payeeType = $this->payee_type;
          $payeeAccount = $this->payee_account;
          $amount = $this->amount;
          $remark = $this->remark;
  
          if (empty($transNo)) {
              throw new PayException('请传入 商户转账唯一订单号');
          }
  
          if (empty($payeeType) || ! in_array($payeeType, ['ALIPAY_USERID', 'ALIPAY_LOGONID'])) {
              throw new PayException('请传入收款账户类型');
          }
  
          if (empty($payeeAccount)) {
              throw new PayException('请传入转账帐号');
          }
  
          if (empty($amount) || bccomp($amount, 0, 2) !== 1) {
              throw new PayException('请输入转账金额，且大于0');
          }
  
          if (bccomp($amount, Config::TRANS_FEE, 2) !== -1 && empty($remark)) {
              throw new PayException('转账金额大于等于' . Config::TRANS_FEE, '必须设置 remark');
          }
      }
docs: 检查参数是否合法
  @author helei