fix: subscribers may not be queried

aspnet-core/modules/message/LINGYUN.Abp.MessageService.Domain/LINGYUN/Abp/MessageService/Notifications/NotificationStore.cs

@@ -207,21 +207,9 @@ namespace LINGYUN.Abp.MessageService.Notifications
         {
             using (_currentTenant.Change(tenantId))
             {
-                var userSubscriptions = new List<UserSubscribe>();
-
-                if (identifiers == null)
-                {
-                    userSubscriptions = await _userSubscribeRepository
-                        .GetUserSubscribesAsync(notificationName, null, cancellationToken);
-                }
-                else
-                {
-                    userSubscriptions = await _userSubscribeRepository
-                        .GetUserSubscribesAsync(
-                            notificationName,
-                            identifiers.Select(ids => ids.UserId),
-                            cancellationToken);
-                }
+                var userIds = identifiers?.Select(ids => ids.UserId);
+                var userSubscriptions = await _userSubscribeRepository
+                    .GetUserSubscribesAsync(notificationName, userIds, cancellationToken);
 
                 return _objectMapper.Map<List<UserSubscribe>, List<NotificationSubscriptionInfo>>(userSubscriptions);
             }

aspnet-core/modules/message/LINGYUN.Abp.MessageService.EntityFrameworkCore/LINGYUN/Abp/MessageService/Subscriptions/EfCoreUserSubscribeRepository.cs

@@ -29,7 +29,7 @@ namespace LINGYUN.Abp.MessageService.Subscriptions
             var userSubscribes = await (await GetDbSetAsync())
                 .Distinct()
                 .Where(x => x.NotificationName.Equals(notificationName))
-                .WhereIf(userIds != null, x => userIds.Contains(x.UserId))
+                .WhereIf(userIds?.Any() == true, x => userIds.Contains(x.UserId))
                 .AsNoTracking()
                 .ToListAsync(GetCancellationToken(cancellationToken));