private void StopVideo() { if (m_CurPlayState != PlayState.PlayStop && m_CurPlayState != PlayState.None) { if (PlayCtrl.PlayM4_Stop(m_lPort)) { if (PlayCtrl.PlayM4_CloseFile(m_lPort)) { if (PlayCtrl.PlayM4_FreePort(m_lPort)) { m_CurPlayState = PlayState.PlayStop; SetCtrlEnable(); } } else { uint error = PlayCtrl.PlayM4_GetLastError(m_lPort); } } else { uint error = PlayCtrl.PlayM4_GetLastError(m_lPort); } } }