void TestButton()
{
int hr;
int pulButtonIndex;
IDvdCmd ppCmd = null;
hr = m_idc2.ShowMenu(DvdMenuId.Title, DvdCmdFlags.Flush, out ppCmd);
DsError.ThrowExceptionForHR(hr);
DsRect pRect = new DsRect();
hr = m_idi2.GetButtonRect(1, pRect);
//ThrowExceptionForHR(hr);
hr = m_idi2.GetButtonAtPosition(new Point(130, 130), out pulButtonIndex);
DsError.ThrowExceptionForHR(hr);
Debug.Assert(pulButtonIndex == 1, "TestButton");
}