public InvoicesViewModel(IInvoiceAppService appService, IServiceProvider serviceProvider, IEventAggregator eventAggregator)
{
AppService = appService;
_serviceProvider = serviceProvider;
EventAggregator = eventAggregator;
SelectedCommand = new DelegateCommand <object[]>(OnItemSelected);
CreateCommand = new DelegateCommand(Create);
UpdateCommand = new DelegateCommand(Update);
ImportCommand = new DelegateCommand(Print);
DeleteCommand = new DelegateCommand(Delete);
Items = new ObservableCollection <InvoiceDto>();
Items.AddRange(AppService.GetListAsync().Result.OrderByDescending(c => c.CreationTime));
EventAggregator.GetEvent <InvoiceUpdatedEvent>().Subscribe(OnInvoiceUpdated);
EventAggregator.GetEvent <InvoiceDeletedEvent>().Subscribe(OnInvoiceDeleted);
EventAggregator.GetEvent <InvoiceAddedEvent>().Subscribe(OnInvoiceAdded);
// Document = new InvoiceDocument ();
}