转移.net core 3.1，为.NET 5做准备

OpenAuth.Repository/Core/Entity.cs

@@ -1,12 +1,29 @@
 using System;
+using System.ComponentModel;
 
-namespace OpenAuth.Repository.Domain
+namespace OpenAuth.Repository.Core
 {
-    public abstract class Entity
+    /// <summary>
+    /// 主键为字符串的实体基类，为系统默认的实体类型
+    /// </summary>
+    public class Entity : BaseEntity
     {
+        [Browsable(false)]
         public string Id { get; set; }
+        
+        /// <summary>
+        /// 判断主键是否为空，常用做判定操作是【添加】还是【编辑】
+        /// </summary>
+        /// <returns></returns>
+        public override bool KeyIsNull()
+        {
+            return string.IsNullOrEmpty(Id);
+        }
 
-        public Entity()
+        /// <summary>
+        /// 创建默认的主键值
+        /// </summary>
+        public override void GenerateDefaultKeyVal()
         {
             Id = Guid.NewGuid().ToString();
         }