让CListView响应Ctrl+A

BOOL CUserManageDlg::PreTranslateMessage(MSG* pMsg)
{
 if (pMsg->message==WM_KEYDOWN)
 {
  if (pMsg->hwnd==GetDlgItem(IDC_LIST1)->m_hWnd)
  {
   switch (pMsg->wParam)
   {
   case 'A':
     if (::GetKeyState(VK_CONTROL)<0)
     {
      for (int i=0;i<m_ListCtrl.GetItemCount();i++)
      {
       m_ListCtrl.SetItemState(i,LVIS_SELECTED|LVIS_FOCUSED,LVIS_SELECTED|LVIS_FOCUSED);
      }
     }
     return TRUE;
   }
  }
 }
 return CDialog::PreTranslateMessage(pMsg);
}