how to get the name of the files which is there in a specified folder

private void button1_Click(object sender, RoutedEventArgs e)
        {
            if (Directory.Exists("C:\\sm") == true)
            {

                string[] files = Directory.GetFiles("C:\\sm");
                if (files.Length == 0)
                {
                    MessageBox.Show("There is no files to collect!");

                }
                else
                {
                    foreach (string f in files)
                    {

                        listBox1.Items.Add(System.IO.Path.GetFileName(f).ToString());

                    }
                }

            }
        }