ListCtrl : GetHeaderCtrl() Renvoie NULL

Pour ceux que ca interresseraient.....


de Michael K. O'Neill <MikeAThon2000@nospam.hotmail.com>



"I noticed this too. If the list control is created as part of a dialog
template (for example) then the HWND of the header control exists inside of
the PreSubclassWindow function, whereas if the list control is created
dynamically (with a call to CListCtrl::Create()) then it does not.

I solved the problem by PostMessage'ing a user-defined message to myself
from inside of the PreSubclassWindow function. In the handler for the
user-defined message, the HWND for the header always exists, regardless of
how the list control was created, and I subclass the header from inside this
handler (and not from inside the PreSubclassWindow function).

I think it works because the user-defined message is posted at the end of
the message queue and is therefore handled at a later time, when everything
has "settled down" and both the list control and its header both have been
created.

Mike"


"Dominique de LAPASSE" <dominique.delapasse@wanadoo.fr> a écrit dans le
message de news: 4254ee79$0$25055$8fcfb975@news.wanadoo.fr...

Bonjour,

Lors de la creation dynamique d une CListCtrlEx ( derivée de CListCtrl ),
Le code suivant est appelé

void CListCtrlEx::PreSubclassWindow()
{
ASSERT( GetStyle() & LVS_REPORT );

CListCtrl::PreSubclassWindow();

VERIFY( m_Headers.SubclassWindow( GetHeaderCtrl()->GetSafeHwnd() ) );
}


... et dans GetHeaderCtrl()
HWND hWnd = (HWND) ::SendMessage(m_hWnd, LVM_GETHEADER, 0, 0);

la valeur hwnd est egal à NULL, ce qui cause un arret dans le VERIFY

Pourquoi ?

Alors que pour une liste creee en statique, la valeur hwnd est differente

de

NULL;


Faut il specifier quelque chose de precis lors de la creation dynamique de
la liste concernant le Header ?

Merci

Dominique