void OnHenRefresh(object param) { IList <Hen> henList = null; henList = henService.GetAll(); var henListItem = Mapper.Map <IList <Hen>, IList <HenListItem> >(henList); var houseList = houseService.GetAll(); foreach (var listItem in henListItem) { var house = houseList.FirstOrDefault(h => h.Id == listItem.HouseId); if (house == null) { continue; } listItem.HouseName = house.Name; } Hens = new ObservableCollection <HenListItem>(henListItem); DeleteCommand.EntityId = Guid.Empty; }