官方文檔：https://pay.weixin.qq.com/wiki/doc/api/native.php?chapter=9_5
## 函數
```
/**
* 微信支付 - 退款查詢
* 微信訂單號、商戶訂單號、微信訂單號、微信退款單號選填至少一個，微信退款單號優先：
* @param $transaction_id 微信訂單號
* @param $out_trade_no 商戶訂單號
* @param $out_refund_no 商戶退款單號
* @param $refund_id 微信退款單號
*/
function wxpayRefundQuery($transaction_id,$out_trade_no='',$out_refund_no='',$refund_id='')
{
//導入 WxPay.Api.php 類
import('WxpayAPI.lib.WxPay',EXTEND_PATH,'.Api.php');
//導入 WxPay.Data.php 類
import('WxpayAPI.lib.WxPay',EXTEND_PATH,'.Data.php');
$input = new WxPayRefundQuery();
$input->SetTransaction_id($transaction_id); //微信訂單號
$input->SetOut_trade_no($out_trade_no); //商戶訂單號
$input->SetOut_refund_no($out_refund_no); //商戶退款單號
$input->SetRefund_id($refund_id); //微信退款單號
dump(WxPayApi::refundQuery($input));
}
```
## 使用方法
```
// 微信支付 - 退款單查詢
public function refundQueryTest()
{
// 微信訂單號 查詢
//wxpayRefundQuery('4200000011201709193042132589');
// 商戶訂單號 查詢
//wxpayRefundQuery('','2017091910048541');
// 商戶訂單號 查詢(注意：這里查的是 out_refund_no_0 而不是out_refund_no)
//wxpayRefundQuery('','','140480710220170919233847');
// 商戶訂單號 查詢(注意：這里查的是 refund_id_0)
wxpayRefundQuery('','','','50000504262017091901789042036');
}
```
## 回調結果
```
array(21) {
["appid"] => string(18) "wx92dedc49b3405e25"
["cash_fee"] => string(3) "100"
["mch_id"] => string(10) "1404807102"
["nonce_str"] => string(16) "3sCT0kOu5s4Qzvik"
["out_refund_no_0"] => string(24) "140480710220170919233847"
["out_trade_no"] => string(16) "2017091910048541"
["refund_account_0"] => string(29) "REFUND_SOURCE_UNSETTLED_FUNDS"
["refund_channel_0"] => string(8) "ORIGINAL"
["refund_count"] => string(1) "1"
["refund_fee"] => string(2) "10"
["refund_fee_0"] => string(2) "10"
["refund_id_0"] => string(29) "50000504262017091901789042036"
["refund_recv_accout_0"] => string(25) "工商銀行信用卡1776"
["refund_status_0"] => string(7) "SUCCESS"
["refund_success_time_0"] => string(19) "2017-09-20 01:10:18"
["result_code"] => string(7) "SUCCESS"
["return_code"] => string(7) "SUCCESS"
["return_msg"] => string(2) "OK"
["sign"] => string(32) "5A3CCE18590454385B11C0BB4634A55F"
["total_fee"] => string(3) "100"
["transaction_id"] => string(28) "4200000011201709193042132589"
}
```
## 官方示例如下：
