public static ProductsObserver GetInstance(Employee empl) { if (State == null) { State = new ProductsObserver(empl); } if (State.employee.Id != empl.Id) { State = new ProductsObserver(empl); } return(State); }
private void ShowAllProducts_Click(object sender, RoutedEventArgs e) { WorkingArea.Content = ProductsObserver.GetInstance(employee); }