接上篇，微信公众号支付申请退款

Controller

    [HttpGet("TestRefund")]
    public void TestRefund()
    {
        _ticketRepository.TestRefund();
    }

Interface

    (bool result, string msg) TestRefund();

业务仓储

    public (bool result,string msg) TestRefund()
    {
        ApplyRefund apply = new ApplyRefund()
        {
            notify_url = $"xxx", //退款成功的回调地址
            transaction_id = "", //微信订单号
            refund_fee = "1",    //单位：分
            total_fee = "1"
        };

        var result = _wxHelper.ApplyRefund(apply);
        //处理业务逻辑
        
        return (true,"success");
    }

用到的实体

public class ApplyRefund
{
    /// <summary>
    /// 微信订单号（和out_trade_no二传一，优先级transaction_id>out_trade_no）
    /// </summary>
    public string transaction_id { get; set; }
    /// <summary>
    /// 商户订单号（和transaction_id二传一，优先级transaction_id>out_trade_no）
    /// </summary>
    public string out_trade_no { get; set; }
    /// <summary>
    /// 订单总金额（分）
    /// </summary>
    public string total_fee { get; set; }
    /// <summary>
    /// 退款金额（分）
    /// </summary>
    public string refund_fee { get; set; }
    /// <summary>
    /// 退款回调地址
    /// </summary>
    public string notify_url { get; set; }
}

帮助方法

    /// <summary>
    /// 退款
    /// </summary>
    /// <param name="transaction_id"></param>
    /// <param name="out_trade_no"></param>
    /// <param name="total_fee"></param>
    /// <param name="refund_fee"></param>
    /// <returns></returns>
    public string ApplyRefund(ApplyRefund dto)
    {
        _logger.LogWarning("Refund", "Refund is processing...");

        WxPayData data = new WxPayData();
        if (!string.IsNullOrEmpty(dto.transaction_id))//微信订单号存在的条件下，则已微信订单号为准
        {
            data.SetValue("transaction_id", dto.transaction_id);
        }
        else//微信订单号不存在，才根据商户订单号去退款
        {
            data.SetValue("out_trade_no", dto.out_trade_no);
        }

        data.SetValue("total_fee", int.Parse(dto.total_fee));//订单总金额
        data.SetValue("refund_fee", int.Parse(dto.refund_fee));//退款金额
        data.SetValue("out_refund_no", GenerateOutTradeNo());//随机生成商户退款单号
        data.SetValue("op_user_id", "xxx");//操作员，默认为商户号
        data.SetValue("notify_url", dto.notify_url);//操作员，默认为商户号

        WxPayData result = Refund(data);//提交退款申请给API，接收返回数据
        return result.ToPrintStr();
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="inputObj"></param>
    /// <param name="timeOut"></param>
    /// <returns></returns>
    public WxPayData Refund(WxPayData inputObj, int timeOut = 6)
    {
        string url = "https://api.mch.weixin.qq.com/secapi/pay/refund";
        //检测必填参数
        if (!inputObj.IsSet("out_trade_no") && !inputObj.IsSet("transaction_id"))
        {
            throw new Exception("退款申请接口中，out_trade_no、transaction_id至少填一个！");
        }
        else if (!inputObj.IsSet("out_refund_no"))
        {
            throw new Exception("退款申请接口中，缺少必填参数out_refund_no！");
        }
        else if (!inputObj.IsSet("total_fee"))
        {
            throw new Exception("退款申请接口中，缺少必填参数total_fee！");
        }
        else if (!inputObj.IsSet("refund_fee"))
        {
            throw new Exception("退款申请接口中，缺少必填参数refund_fee！");
        }
        else if (!inputObj.IsSet("op_user_id"))
        {
            throw new Exception("退款申请接口中，缺少必填参数op_user_id！");
        }

        inputObj.SetValue("appid", "xxx");//公众账号ID
        inputObj.SetValue("mch_id", "xxx");//商户号
        inputObj.SetValue("nonce_str", Guid.NewGuid().ToString().Replace("-", ""));//随机字符串
        inputObj.SetValue("sign_type", WxPayData.SIGN_TYPE_MD5);//签名类型
        inputObj.SetValue("sign", inputObj.MakeSign());//签名

        string xml = inputObj.ToXml();
        var start = DateTime.Now;

        string response = _webHelper.Post(xml, url, true, timeOut);//调用HTTP通信接口提交数据到API

        var end = DateTime.Now;
        //int timeCost = (int)((end - start).TotalMilliseconds);//获得接口耗时

        //将xml格式的结果转换为对象以返回
        WxPayData result = new WxPayData();
        result.FromXml(response);

        //ReportCostTime(url, timeCost, result);//测速上报

        return result;
    }

    public string RefundQuery(string refund_id, string out_refund_no, string transaction_id, string out_trade_no)
    {
        _logger.LogWarning("RefundQuery is processing...");

        WxPayData data = new WxPayData();
        if (!string.IsNullOrEmpty(refund_id))
        {
            data.SetValue("refund_id", refund_id);//微信退款单号，优先级最高
        }
        else if (!string.IsNullOrEmpty(out_refund_no))
        {
            data.SetValue("out_refund_no", out_refund_no);//商户退款单号，优先级第二
        }
        else if (!string.IsNullOrEmpty(transaction_id))
        {
            data.SetValue("transaction_id", transaction_id);//微信订单号，优先级第三
        }
        else
        {
            data.SetValue("out_trade_no", out_trade_no);//商户订单号，优先级最低
        }

        WxPayData result = RefundQuery(data);//提交退款查询给API，接收返回数据
        return result.ToPrintStr();
    }

【.net core】微信公众号JSAPI支付--申请退款