C / C++ / MFC

ON_NOTIFY(NM_CUSTOMDRAW, IDC_TREE1, OnTreeCustomDraw)

void CMyDlg::OnTreeCustomDraw(NMHDR* pNMHDR, LRESULT* pResult) 
{
	*pResult = 0;
	NMTVCUSTOMDRAW *nmtv = (NMTVCUSTOMDRAW *)pNMHDR;

	// TODO: Add your control notification handler code here

	switch (nmtv->nmcd.dwDrawStage)
	{
	case CDDS_PREPAINT:
		*pResult = CDRF_NOTIFYITEMDRAW;
		return;

	case CDDS_POSTPAINT:
		break;

	case CDDS_ITEMPREPAINT:
		TRACE1("uItemState=%x\n", nmtv->nmcd.uItemState);
		{
			BOOL bState = TreeView_GetCheckState (::GetDlgItem (GetSafeHwnd (), IDC_TREE1), (HTREEITEM) nmtv->nmcd.dwItemSpec);
			TRACE1("   Check state = %i\n", bState);
                        // Now do whatever you like!
		}
		break;

	case CDDS_ITEMPOSTPAINT:
	case CDDS_ITEMPREERASE:
	case CDDS_ITEMPOSTERASE:
		break;
	default:
		TRACE1("Unexpected draw state =%i", nmtv->nmcd.dwDrawStage);
		break;
	}

	
}

// Copied from MSDN
BOOL TreeView_GetCheckState(HWND hwndTreeView, HTREEITEM hItem)
{
    TVITEM tvItem;

    // Prepare to receive the desired information.
    tvItem.mask = TVIF_HANDLE | TVIF_STATE;
    tvItem.hItem = hItem;
    tvItem.stateMask = TVIS_STATEIMAGEMASK;

    // Request the information.
    TreeView_GetItem(hwndTreeView, &tvItem);

    // Return zero if it's not checked, or nonzero otherwise.
    return ((BOOL)(tvItem.state >> 12) -1);
}

POSITION pstPos = GetFirstSelectedItemPosition();
while( pstPos )
{
   // Get selected item index
   const int nItem = GetNextSelectedItem( pstPos );

   // Deselect selected item
   SetItemState( nItem, 0, LVIS_SELECTED );
}