$refund->setParameter("out_trade_no", "{$out_trade_no}");
//商户订单号
$refund->setParameter("out_refund_no", "{$out_refund_no}");
//商户退款单号
$refund->setParameter("total_fee", "{$total_fee}");
//总金额
$refund->setParameter("refund_fee", "{$refund_fee}");
//退款金额
$refund->setParameter("op_user_id", WxPayConf::MCHID);
//操作员
//非必填参数，商户可根据实际情况选填
//$refund->setParameter("sub_mch_id","XXXX");//子商户号
//$refund->setParameter("device_info","XXXX");//设备号
//$refund->setParameter("transaction_id","XXXX");//微信订单号
//调用结果
$refundResult = $refund->getResult();
//商户根据实际情况设置相应的处理流程,此处仅作举例
if ($refundResult["return_code"] == "FAIL") {
echo "通信出错：" . $refundResult['return_msg'] . "<br>";
} else {
echo "业务结果：" . $refundResult['result_code'] . "<br>";
echo "错误代码：" . $refundResult['err_code'] . "<br>";
echo "错误代码描述：" . $refundResult['err_code_des'] . "<br>";
echo "公众账号ID：" . $refundResult['appid'] . "<br>";
echo "商户号：" . $refundResult['mch_id'] . "<br>";
echo "子商户号：" . $refundResult['sub_mch_id'] . "<br>";
echo "设备号：" . $refundResult['device_info'] . "<br>";
echo "签名：" . $refundResult['sign'] . "<br>";
echo "微信订单号：" . $refundResult['transaction_id'] . "<br>";
echo "商户订单号：" . $refundResult['out_trade_no'] . "<br>";
echo "商户退款单号：" . $refundResult['out_refund_no'] . "<br>";
