BEGIN_MESSAGE_MAP(CListCtrl_Column_Picker, CListCtrl)
    ON_MESSAGE(LVM_SETCOLUMNWIDTH, OnSetColumnWidth)
    ON_NOTIFY_EX(HDN_BEGINTRACKA, 0, OnHeaderBeginResize)
    ON_NOTIFY_EX(HDN_BEGINTRACKW, 0, OnHeaderBeginResize)
END_MESSAGE_MAP()

BOOL CListCtrl_Column_Picker::OnHeaderBeginResize(UINT, NMHDR* pNMHDR, LRESULT* pResult)
{
    // Check that column is allowed to be resized
    NMHEADER* pNMH = (NMHEADER*)pNMHDR;
    int nCol = (int)pNMH->iItem;
    if (!IsColumnVisible(nCol))
    {
        *pResult = TRUE;    // Block resize
        return TRUE;        // Block event
    }
    return FALSE;
}

LRESULT CListCtrl_Column_Picker::OnSetColumnWidth(WPARAM wParam, LPARAM lParam)
{
    // Check that column is allowed to be resized
    int nCol = (int)wParam;
    if (!IsColumnVisible(nCol))
    {
        return FALSE;
    }

    // Let the CListCtrl handle the event
    return DefWindowProc(LVM_SETCOLUMNWIDTH, wParam, lParam);
}