protected override void OnHandleCreated(EventArgs e)
{
base.OnHandleCreated(e);
var x = new COMBOBOXINFO();
x.cbSize = (uint)Marshal.SizeOf(typeof(COMBOBOXINFO));
var b = User32.GetComboBoxInfo(Handle, ref x);
_listBoxDefaultWndProc = NativeUtility.SetWindowProc(x.hwndList, _listBoxWndProc);
}