PocketBook/Sources/BookApp/ViewModel/ViewModelNavigation.cs

using ToolKit;
using System.Windows.Input;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;

namespace BookApp.ViewModel
{
    public class ViewModelNavigation : BaseViewModel
    {
        private ViewModelMenuItem _selectedItem;
        public ViewModelMenuItem SelectedItem
        {
            get { return _selectedItem; }
            set { SetProperty(ref _selectedItem, value); }
        }

        public ICommand ItemSelectedCommand { get; private set; }

        public ViewModelNavigation()
        {
            ItemSelectedCommand = new Command(async () => await OnItemSelected(SelectedItem));
        }

        private async Task OnItemSelected(ViewModelMenuItem selectedItem)
        {
            SelectedItem = selectedItem;

            if (string.IsNullOrEmpty(SelectedItem?.Route))
                return;

            try
            {
                await Shell.Current.GoToAsync(selectedItem.Route);
                selectedItem = null;
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"Navigation failed: {ex.Message}");
            }
        }

        async void ButtonTous(object sender, EventArgs args)
        {
            await Shell.Current.GoToAsync("TousPage");
        }

        async void ButtonAuteur(object sender, EventArgs args)
        {
            await Shell.Current.GoToAsync("FiltragePage");
        }
    }
}