void CBaseView::Delete_Group()
{
    CBaseDoc* pDoc = GetDocument();
    CListCtrl& list = GetListCtrl();   
    CChildFrame* pParent = (CChildFrame*)GetParent();
    int page = pParent->m_PageBar.GetSelectPage() ;
    int start = (page-1)*36 ;

    unsigned int groupno = 0 ;
    int nidx  =-1;
    POSITION pos=list.GetFirstSelectedItemPosition(); //pos选中的首行位置
    if (pos != NULL)
    {
        nidx = list.GetNextSelectedItem(pos) ;
        if ((start + nidx)> pDoc->GetDataSize())
        {
            return ;
        }
        CString GroupNoRow = pDoc->GetData(nidx + start) ;
        CString GroupNo = getdatano( GroupNoRow , 1) ;        
        groupno = _ttoi(GroupNo) ;

    }
    else{
        AfxMessageBox(_T("选择要删除的组！")) ;
        return;
    }
    TCHAR buf[30] = {0} ;
    wsprintf(buf ,_T("确认删除组 %d ？") ,groupno) ;

    if(MessageBox( buf, _T("确认"), MB_ICONQUESTION | MB_OKCANCEL) == IDCANCEL)
    {
        return ;
    }

    grp_table_del_by_grpNum_t group_client ;
    memset(&group_client , 0 , sizeof(group_client));        
    group_client. = user_group_del_by_grpnum ;
    group_client.operateHead.operateType = Delete ;
    group_client.operateHead.nmsClientPac.dev_code =  devcode ;
    group_client.operateHead.nmsClientPac.system_source = nms_sys;
    group_client.operateHead.nmsClientPac.pac_msg_serial =  create_msg_searial() ;
    group_client.operateHead.nmsClientPac.packet_len = sizeof(group_client) ;
    group_client.operateHead.nmsClientPac.pac_msg_type = database_handle ;

    CString strDisId = list.GetItemText(nidx , 7) ;
    group_client.dispatchID  = _ttoi(strDisId) ;

    if (group_client.dispatchID <= 0)
    {
        //    return ;
    }

    group_client.grpNum = groupno ;
    bfdx_send((char*)&group_client , sizeof(group_client)) ;



}

哪里有问题？是这边吗？
    POSITION pos=list.GetFirstSelectedItemPosition(); //pos选中的首行位置
    if (pos != NULL)
    {
        nidx = list.GetNextSelectedItem(pos) ;
一般这样用 :
    POSITION pos=list.GetFirstSelectedItemPosition(); //pos选中的首行位置
    while(pos != NULL)
    {
        nidx = list.GetNextSelectedItem(pos) ;
。。。
    }