C / C++ / MFC

void CDlgLists::OnItemchangedList2(NMHDR* pNMHDR, LRESULT* pResult) 
{
	NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
	if (pNMListView->uOldState == 0 && pNMListView->uNewState == 0)
		return;	// No change







	BOOL bPrevState = (BOOL)(((pNMListView->uOldState & 
				LVIS_STATEIMAGEMASK)>>12)-1);   // Old check box state


	if (bPrevState < 0)	// On startup there's no previous state 
		bPrevState = 0; // so assign as false (unchecked)


	// New check box state
	BOOL bChecked=(BOOL)(((pNMListView->uNewState & LVIS_STATEIMAGEMASK)>>12)-1);



	if (bChecked < 0)
		bChecked = 0;



	BOOL bNameClicked = (bChecked < 0);



	if (bPrevState == bChecked) // No change in check box
		return;



	DWORD dwPos = ::GetMessagePos();

	CPoint point((int) LOWORD(dwPos), (int) HIWORD(dwPos));

	m_list2.ScreenToClient(&point);

	int nIndex;



	if ((nIndex = m_list2.HitTest(point)) == -1) return;


	OptStateMap &optStateMap = keyOptMap[activeKey];


	if (optStateMap.empty())
			GetOpts(activeKey,optStateMap);


	CString temp;
	temp.Format("index is %d ",nIndex);

	AfxMessageBox (temp);


	CString opt = m_list2.GetItemText(nIndex,0);


	keyOptMap[activeKey][opt] = !keyOptMap[activeKey][opt];
	
	*pResult = 0;
}