PHP implements the full version of mini program refund

    /**
     * 退款
     * @author:大脸猫脸大
     */
    public function refund()
    {
        import("Vendor.Wxpay.lib.WxPay#Api", "", ".php");
        $orderSn =  I("ordersn", "", "trim");
        $map = array('ordersn'=> $orderSn);
        $order = M("Order")->where($map)->find();
        if (!$order) {
            $result['code'] = 0;
            $result['msg'] = '未找到订单';
            $this->ajaxReturn($result);
        }
        $input = new \WxPayRefund();
        $input->SetTotal_fee($order['price']*100);
        $input->SetRefund_fee($order['price']*100);
        $input->SetOut_refund_no("R".$orderSn);
        $input->SetOut_trade_no("$orderSn");
        $input->SetOp_user_id(\WxPayConfig::MCHID);
        $refundOrder = \WxPayApi::refund($input);
        //file_put_contents(__DIR__."/refund.log", var_export($refundOrder, true). "\r\n" , FILE_APPEND);
        if ($refundOrder['result_code'] == 'SUCCESS' && $refundOrder['return_code'] == 'SUCCESS') {
            $result['code'] = 1;
            $result['data'] =  $refundOrder['transaction_id'];
            $this->ajaxReturn($result);
        }
        else {
            $result['code'] = 0;
            $result['msg'] =  $refundOrder['err_code'];
            $this->ajaxReturn($result);
        }
    }