单击ListCtrl时，LVN_ITEMCHANGED响应3次

void CTestWin32Dlg::OnLvnItemchangedList(NMHDR *pNMHDR, LRESULT *pResult)
{
    LPNMLISTVIEW pNMLV = reinterpret_cast<LPNMLISTVIEW>(pNMHDR);
    // TODO: Add your control notification handler code here

    if( pNMLV->uChanged == LVIF_STATE &&
        pNMLV->uNewState == (LVIS_FOCUSED | LVIS_SELECTED)) {
            int nItem = pNMLV->iItem;

    }

    *pResult = 0;

}