public MainWindowViewModel(IViewModelFactory factory) { addOrderCommand = new DelegateCommand(() => Current = factory.CreateAddOrderViewModel()); reportCommand = new DelegateCommand(() => Current = factory.CreateReportViewModel()); assignMechanicCommand = new DelegateCommand(() => Current = factory.CreateAssignMechanicViewModel()); completeOrderCommand = new DelegateCommand(() => Current = factory.CreateCompleteOrderViewModel()); }