private void AddLabourCmd(object model) { ErrorMessage = ""; var labour = model as Labour; if (labour.Payment < 1 || labour.PaymentDate == default(DateTime) || SelectedContractor.ContractorId == 0 || labour.WorkType.WorkTypeId == 0) { ErrorMessage = "*Please check the entry. Some field's Values are missing."; return; } labour.SiteId = SiteId; labour.CreateDate = DateTime.Now; labour.Contractor = Contractors.Single(x => x.ContractorId == SelectedContractor.ContractorId); _repositoryManager.AddLabourPayment(labour); LabourToAdd = new Labour(); LabourToAdd.Contractor = Contractors.First(); LabourToAdd.WorkType = WorkTypes.First(); SelectedContractor = ContractorList.First(); Labours = new ObservableCollection <Labour>(_repositoryManager.GetLabourPayments(SiteId)); OnPropertyChanged(nameof(LabourToAdd)); OnPropertyChanged(nameof(SelectedContractor)); }