ListCtrl的问题

[smileconfess]

我想获得ListCtrl某一格的Item和SubItem的值,下面的程序哪儿有错?
void CUuDlg::OnDblclkList1(NMHDR* pNMHDR, LRESULT* pResult)
{
// TODO: Add your control notification handler code here
CPoint pt;
::GetCursorPos(&pt);
ScreenToClient(&pt);
LVHITTESTINFO lvinfo;
lvinfo.pt = pt;
lvinfo.flags = LVHT_ABOVE;

int nItem = m_ListCtrl.SubItemHitTest(&lvinfo);//为什么nItem和SubItem总是-1??
int b = lvinfo.iSubItem;
if(nItem != -1)
{
CString strtemp;
strtemp.Format("双击了第%d行第%d列", lvinfo.iItem, lvinfo.iSubItem);
AfxMessageBox(strtemp);
}

*pResult = 0;
}

[flyelf]

m_listctrl.ScreenToClient(&pt);

[lixiaosan]

晕。。上面是我的代码