listbox elemeinek szinkron kiválasztása

    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
      index1 = listBox1.SelectedIndex;
      if (index1 > -1)
      {
        if (!listBox2.GetSelected(index1))
        {
          listBox2.SetSelected(index1, true);
        }
      }
    }

    private void listBox2_SelectedIndexChanged(object sender, EventArgs e)
    {
      index2 = listBox2.SelectedIndex;
      if (index2 > -1)
      {
        if (!listBox1.GetSelected(index2))
        {
          listBox1.SetSelected(index2, true);
        }
      }
    }