MVVM работа с несколькими окнами

public int Id{ get; set; }

public ICommand SendCommand { get; }
private bool CanSendCommand(object p) =>
    true;
private void OnSendCommand(object p)
{
  Choose();
}
 
private int Choose()
{
    var id = 0;
    _secondViewModel  = new SecondViewModel ();
    var window = new Window();
    window.Content = new SecondView(window);
    window.DataContext = _secondViewModel;
    window.Closed += (sender, e) => id =_secondViewModel.Id;
    window.Show();
    
    return id;
}

window.ShowDialog();

public Func<int> Choose {get; set;}
 
private int ChooseExecute() => Choose();

MainViewModel mainVM = ....;
mainVM.Choose  = () =>
{
    var id = 0;
    _secondViewModel  = new SecondViewModel ();
    var window = new Window();
    window.Content = new SecondView(window);
    window.DataContext = _secondViewModel;
    window.Closed += (sender, e) => id =_secondViewModel.Id;
    window.Show();
    
    return id;
};

internal class WindowService : IWindowService
    {
        private readonly IViewModelsService _viewModelsService;
 
        public WindowService(IViewModelsService viewModelsService)
        {
            _viewModelsService = viewModelsService;
        }
        public Window GetWindow(IBaseViewModel viewModel)
        {
            var window = _viewModelsService.GetWindow(viewModel);
 
            window.DataContext = viewModel;
 
            return window;
        }
 
        public void CloseWindow(IBaseViewModel viewModel)
            => GetWindow(viewModel).Close();

public class ViewModelsService : IViewModelsService
    {
        private readonly Dictionary<Type, Func<ContentControl>> _dict = new Dictionary<Type, Func<ContentControl>>();
 
        public IViewModelsService Register<TViewModelType, TViewType>()
            where TViewType : ContentControl, new()
            where TViewModelType : IBaseViewModel
        {
            _dict[typeof(TViewModelType)] = () => new TViewType();
 
            return this;
        }
 
        public Window GetWindow(IBaseViewModel viewModel)
        {
            var result = GetControl(viewModel);
 
            if (!(result is Window window))
                throw new Exception($"{result.GetType()} is not window");
 
            return window;
        }
 
        public ContentControl GetControl(IBaseViewModel viewModel)
        {
            var parentTypes = GetParentTypes(viewModel.GetType());
 
            foreach (var parentType in parentTypes)
            {
                if (_dict.TryGetValue(parentType, out var res))
                    return res();
            }
 
            throw new Exception($"ViewModel {viewModel.GetType().Name} is not registered");
        }

_windowService.CloseWindow(this);