Sample of tracking changes

ChangeTrackerSample.cs

private async void StartTracking_Click(object sender, RoutedEventArgs e)
{
    FolderPicker p = new FolderPicker();
    p.FileTypeFilter.Add(".txt");
    p.FileTypeFilter.Add(".jpg");
    var f = await p.PickSingleFolderAsync();
    var t = f.TryGetChangeTracker();
    if (t != null)
    {
        t.Enable();
    }
    var s = await f.CreateFileAsync("clippy.txt", CreationCollisionOption.OpenIfExists);
    await FileIO.AppendTextAsync(s, "muffffffins");
    var tok = StorageApplicationPermissions.FutureAccessList.Add(f);
    ApplicationData.Current.LocalSettings.Values["path"] = tok;
}

private async void FetchChanges_Click(object sender, RoutedEventArgs e)
{
    var tok = (string)ApplicationData.Current.LocalSettings.Values["path"];
    var f = await StorageApplicationPermissions.FutureAccessList.GetFolderAsync(tok);
    var t = f.TryGetChangeTracker();
    if (t != null)
    {
        var r = t.GetChangeReader();
        var changes = await r.ReadBatchAsync();
        foreach (var c in changes)
        {
        }
        await r.AcceptChangesAsync();
    }
}