【新增】完善【退款单】的支付宝退款功能。

CoreCms.Net.IServices/Pay/IAliPayServices.cs

@@ -25,5 +25,16 @@ namespace CoreCms.Net.IServices
         /// <param name="entity">实体数据</param>
         /// <returns></returns>
         Task<WebApiCallBack> PubPay(CoreCmsBillPayments entity);
+
+
+        /// <summary>
+        ///     用户退款
+        /// </summary>
+        /// <param name="refundInfo">退款单数据</param>
+        /// <param name="paymentInfo">支付单数据</param>
+        /// <returns></returns>
+        Task<WebApiCallBack> Refund(CoreCmsBillRefund refundInfo, CoreCmsBillPayments paymentInfo);
+
+
     }
 }