补充部分注释

src/Essensoft.AspNetCore.Payment.WeChatPay/Domain/Certificate.cs

@@ -1,21 +1,33 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Text.Json.Serialization;
+using System.Text.Json.Serialization;
 
 namespace Essensoft.AspNetCore.Payment.WeChatPay.Domain
 {
+    /// <summary>
+    /// 平台证书信息
+    /// </summary>
     public class Certificate : WeChatPayObject
     {
+        /// <summary>
+        /// 序列号
+        /// </summary>
         [JsonPropertyName("serial_no")]
         public string SerialNo { get; set; }
 
+        /// <summary>
+        /// 生效时间
+        /// </summary>
         [JsonPropertyName("effective_time")]
         public string EffectiveTime { get; set; }
 
+        /// <summary>
+        /// 失效时间
+        /// </summary>
         [JsonPropertyName("expire_time")]
         public string ExpireTime { get; set; }
 
+        /// <summary>
+        /// 加密证书信息
+        /// </summary>
         [JsonPropertyName("encrypt_certificate")]
         public EncryptCertificate EncryptCertificate { get; set; }
     }

src/Essensoft.AspNetCore.Payment.WeChatPay/Domain/EncryptCertificate.cs

@@ -2,17 +2,32 @@
 
 namespace Essensoft.AspNetCore.Payment.WeChatPay.Domain
 {
+    /// <summary>
+    /// 加密证书信息
+    /// </summary>
     public class EncryptCertificate : WeChatPayObject
     {
+        /// <summary>
+        /// 加密算法
+        /// </summary>
         [JsonPropertyName("algorithm")]
         public string Algorithm { get; set; }
 
+        /// <summary>
+        /// 加密使用的随机串初始化向量
+        /// </summary>
         [JsonPropertyName("nonce")]
         public string Nonce { get; set; }
 
+        /// <summary>
+        /// 附加数据包
+        /// </summary>
         [JsonPropertyName("associated_data")]
         public string AssociatedData { get; set; }
 
+        /// <summary>
+        /// Base64编码后的密文
+        /// </summary>
         [JsonPropertyName("ciphertext")]
         public string Ciphertext { get; set; }
     }

src/Essensoft.AspNetCore.Payment.WeChatPay/Response/WeChatPayTransactionsNativeResponse.cs

@@ -2,8 +2,19 @@
 
 namespace Essensoft.AspNetCore.Payment.WeChatPay.Response
 {
+    /// <summary>
+    /// Native下单API-返回参数
+    /// 最新更新时间：2020.05.26
+    /// https://pay.weixin.qq.com/wiki/doc/apiv3/wxpay/pay/transactions/chapter3_3.shtml
+    /// </summary>
     public class WeChatPayTransactionsNativeResponse : WeChatPayV3Response
     {
+        /// <summary>
+        /// 二维码链接
+        /// 此URL用于生成支付二维码，然后提供给用户扫码支付。
+        /// 注意：code_url并非固定值，使用时按照URL格式转成二维码即可。
+        /// 示例值：weixin://wxpay/bizpayurl/up?pr=NwY5Mz9&groupid=00
+        /// </summary>
         [JsonPropertyName("code_url")]
         public string CodeUrl { get; set; }
     }