using MVVMHierarchiesDemo.ViewModel; 
using MVVMHierarchiesDemo.Views; 

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Threading.Tasks;

namespace MVVMHierarchiesDemo { 

   class MainWindowViewModel : BindableBase { 
    
      public MainWindowViewModel() { 
         NavCommand = new MyICommand(OnNav); 
      } 

      private CustomerListViewModel custListViewModel = new CustomerListViewModel(); 
      private OrderViewModel orderViewModelModel = new OrderViewModel();

      private BindableBase _CurrentViewModel; 
        
      public BindableBase CurrentViewModel { 
         get { return _CurrentViewModel; } 
         set { SetProperty(ref _CurrentViewModel, value); } 
      } 
        
      public MyICommand NavCommand { get; private set; }

      private void OnNav(string destination) { 
        
         switch (destination) { 
            case "orders": 
               CurrentViewModel = orderViewModelModel; 
               break; 
            case "customers":
               default: 
               CurrentViewModel = custListViewModel; 
               break; 
         } 
      } 
   }
}