private async Task listAsync()
{
if (_cts != null)
{
_cts.Cancel();
}
_cts = new CancellationTokenSource();
lbList.Items.Clear();
var di = new DirectoryInfoEx(tbFolder.Text);
foreach (var item in await di.GetFilesAsync("*", cbRecrusive.IsChecked.Value ?
SearchOption.AllDirectories : SearchOption.TopDirectoryOnly, _cts.Token))
{
lbList.Items.Add(item);
}
}