.NET Core 实现微信小程序支付功能（统一下单）

services.AddSenparcGlobalServices(Configuration)
.AddSenparcWeixinServices(Configuration);

IRegisterService register = RegisterService.Start(env, senparcSetting.Value).UseSenparcGlobal(false, null);
register.UseSenparcWeixin(senparcWeixinSetting.Value, senparcSetting.Value)
 .RegisterTenpayV3(senparcWeixinSetting.Value, "appid");

///<summary>
/// 微信支付回调地址
/// </summary>
/// <returns></returns>
[HttpPost("PayNotifyUrl")]
public ActionResult PayNotifyUrl()
{
 ResponseResult result = new ResponseResult();
 ResponseHandler resHandler = new ResponseHandler(HttpContext);
 string return_code = resHandler.GetParameter("return_code");
 string return_msg = resHandler.GetParameter("return_msg");

 try
 {
  var mch_key = Senparc.Weixin.Config.SenparcWeixinSetting.TenPayV3_Key;
  resHandler.SetKey(mch_key);

  var notifyXml = resHandler.ParseXML();
  bool signFlag = resHandler.IsTenpaySign();
  if (signFlag && return_code.ToUpper() == "SUCCESS")
  {
   string attach = resHandler.GetParameter("attach");
   string device_info = resHandler.GetParameter("device_info");
   string out_trade_no = resHandler.GetParameter("out_trade_no");
   string transaction_id = resHandler.GetParameter("transaction_id");
   string total_fee = resHandler.GetParameter("total_fee");

   PayOrderNotifyParam param = new PayOrderNotifyParam()
   {
    PayNo = out_trade_no,
    Attach = attach,
    PayPrice = decimal.Parse(total_fee) / 100,
    TransactionNo = transaction_id,
   };

   //回调参数说明：https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=9_7&index=3
   //Logger.Info(string.Format("支付回调接收参数成功，notifyXml={0},param={1}", notifyXml, param.SerializeObject()));

   result = Service.PayNotifyUrl(param);
   if (result.errno != 0)
   {
    //回调处理逻辑失败
    Logger.Error(string.Format("支付回调处理失败：支付单号:{0},{1}", param.PayNo, result.errmsg));
   }
   else
   {
    Logger.Info(string.Format("支付回调处理成功,支付单号：{0}", param.PayNo));
    string xml = string.Format(@"<xml>
       <return_code><![CDATA[{0}]]></return_code>
       <return_msg><![CDATA[{1}]]></return_msg>
       </xml>", return_code, return_msg);

    return Content(xml, "text/xml");
   }

  }
  else
  {
   //错误的订单处理
   Logger.Error(string.Format("支付回调接失败，signFlag={0},notifyXml={1}", signFlag, notifyXml));
  }


 }
 catch (Exception ex)
 {
  Logger.Error(string.Format("支付回调异常：Message={0}，StackTrace={1}", ex.Message, ex.StackTrace));
 }

 return Content("fail", "text/xml");
}