后端：

完善注册页面

backend/IM_API/Dtos/Auth/RegisterRequestDto.cs

@@ -4,6 +4,8 @@ namespace IM_API.Dtos.Auth
 {
     public class RegisterRequestDto
     {
+        [EmailAddress(ErrorMessage = "邮箱格式错误")]
+        public string Email { get; set; }
         [Required(ErrorMessage = "用户名不能为空")]
         [MaxLength(20, ErrorMessage = "用户名不能超过20字符")]
         [RegularExpression(@"^[A-Za-z0-9]+$", ErrorMessage = "用户名只能为英文或数字")]

backend/IM_API/Dtos/Group/HandleGroupInviteDto.cs

@@ -5,6 +5,6 @@ namespace IM_API.Dtos.Group
     public class HandleGroupInviteDto
     {
         public int InviteId { get; set; }
-        public GroupInviteState Action { get; set; }
+        public GroupRequestState Action { get; set; }
     }
 }