public async Task <System.Collections.ObjectModel.ObservableCollection <User> > GetUsersFromGroup(string groupId) { if (await EnsureLogin()) { var userGroupService = new UserGroupService(base.AccessToken); var userGroups = await userGroupService.GetUserGroupTableForGroup(groupId); var allUsers = await MobileService.GetTable <User>().ToCollectionAsync(); ObservableCollection <User> groupUsers = new ObservableCollection <User>(); foreach (var userGroup in userGroups) { var user = allUsers.SingleOrDefault(u => u.Id == userGroup.UserId); if (user != null) { groupUsers.Add(user); } } return(groupUsers); } return(null); }