MainWindow.xaml.cs

using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Controls.Primitives;
using Microsoft.UI.Xaml.Data;
using Microsoft.UI.Xaml.Input;
using Microsoft.UI.Xaml.Media;
using Microsoft.UI.Xaml.Navigation;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;

// To learn more about WinUI, the WinUI project structure,
// and more about our project templates, see: http://aka.ms/winui-project-info.

namespace NavigationViewKeyboardAcceleratorsTest
{
    /// <summary>
    /// An empty window that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainWindow : Window
    {
        int count;
        public MainWindow()
        {
            this.InitializeComponent();
            count = 0;
        }

        private void NavigationView_ItemInvoked(NavigationView sender, NavigationViewItemInvokedEventArgs args)
        {
            count++;
            ItemInvokedCount.Text = count.ToString();

            if(args.InvokedItemContainer == Item1)
            {

            }
            else if(args.InvokedItemContainer == Item2)
            {

            }
            else
            {

            }
        }
    }
}