Re: DestroyWindow() not destroying child windows

From:
"Alexander Nickolov" <agnickolov@mvps.org>
Newsgroups:
microsoft.public.vc.atl
Date:
Fri, 27 Oct 2006 13:29:25 -0700
Message-ID:
<#BkyYag#GHA.896@TK2MSFTNGP03.phx.gbl>
How do you know they aren't being destroyed? Do you
subclass them?

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================

"PaulH" <paul.heil@gmail.com> wrote in message
news:1161878716.976991.105390@i3g2000cwc.googlegroups.com...

I have a WTL SDI program where the views can change. To accomplish
this, a SwitchView() function is called and the view to switch to is
specified:

DIALOGS m_CurView; //DIALOGS is an enum with identifiers for each view
std::map<DIALOGS, CBase*> m_mViews;

BOOL CMainFrame::SwitchView(DIALOGS dlg)
{

   if (m_mViews[m_CurView]->BaseIsWindow())
       m_mViews[m_CurView]->BaseDestroyWindow();

   m_CurView = dlg;
   m_hWndClient = m_mViews[m_CurView]->BaseCreate(m_hWnd);
   if (!m_mViews[m_CurView]->BaseIsWindow())
       return FALSE;

   RECT rcWnd = {0};
   GetClientRect(&rcWnd);
   m_mViews[m_CurView]->BaseMoveWindow(&rcWnd, FALSE);
   m_mViews[m_CurView]->BaseShowWindow(SW_SHOW);
   m_mViews[m_CurView]->BaseSetFocus();

   return TRUE;
}

This destroys the current view and creates the requested view. But,
when the DestroyWindow() is called on the current view, the child
windows (such as CStatics) don't get the WM_DESTROY message, so when I
return to the dialog, I get all kinds of nasty failures.

Each view class derives from a CBaseViewT class so that I can specify
them generically in the CMainFrm. (as above in the SwitchView()
function).

class CBase
{
public:
   virtual BOOL BasePreTranslateMessage(MSG* pMsg) = 0;
   virtual HWND BaseCreate(HWND hWndParent, LPARAM dwInitParam = NULL)
= 0;
   virtual BOOL BaseMoveWindow(LPCRECT lpRect, BOOL bRepaint = TRUE) =
0;
   virtual BOOL BaseDestroyWindow() = 0;
   virtual HWND BaseSetFocus() = 0;
   virtual BOOL BaseIsWindow() = 0;
   virtual BOOL BaseShowWindow(int nCmdShow) = 0;
};

template <class T>
class CBaseViewT : public CBase
{
   //...Implementation of virtual functions in CBase() that just call
the CWindow() counterparts
   // For Example:
   BOOL BaseDestroyWindow()
   {
       T* pT = static_cast<T*>(this);
       return pT->DestroyWindow();
   };
};

Can anybody tell me why the child windows of the views aren't being
properly destroyed?

Thanks,
PaulH

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