Re: Dynamically creating CDockablePanes

From:
=?Utf-8?B?TmljayBTY2h1bHR6?= <NickSchultz@discussions.microsoft.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Fri, 2 May 2008 14:58:00 -0700
Message-ID:
<8824E7C6-FA47-487A-9242-49A5028321E5@microsoft.com>
Alright, using PostMessage(WM_CLOSE) got rid of the access violation.
However the docked panel stays painted on the screen(i can also "paint" other
windows in the area as well) until I resize the main window (when the paint
method gets called) The main window only has one control and it is a
CListCtrl.

Thanks Ajay, it looks like I'm getting closer, however these functions don't
get called at all when the CDockablePane is not docked. I am confirming this
by setting breakpoints and watching the thread list in Process Explorer.

"Ajay Kalra" wrote:

On May 2, 5:03 pm, Nick Schultz
<NickSchu...@discussions.microsoft.com> wrote:

OK, I tried overriding both PostNcDestroy and OnPressCloseButton functions
and it still isn't working the way I would like it to...

When I create the window, it starts out docked to the main frame. If I
undock the window and then close it, those functions do not get called. If I
leave it docked, or undock it and dock it again and then close the window,
those functions get called.

After going through those two functions, I then get an Access violation:

Unhandled exception at 0x78a75e55 (mfc90ud.dll) in CanAnalyzer.exe:
0xC0000005: Access violation reading location 0xfeef000e.

and the break point is at the return statement:

LRESULT CWnd::Default()
{
        // call DefWindowProc with the last message
        _AFX_THREAD_STATE* pThreadState = _afxThreadState.GetData();
        return DefWindowProc(pThreadState->m_lastSentMsg.message,
                pThreadState->m_lastSentMsg.wParam, pThreadState->m_lastSentMsg.lParam);

}

Here is the code of the closing functions:

void CGrapher::OnPressCloseButton()
{
        DestroyWindow(); }

void CGrapher::PostNcDestroy(){
        delete this;

}

So i guess I got a couple questions now, why am i getting that access
violation and why wont those functions get called when the CDockablePane is
undocked(floating)?

Thanks for the help,

Nick

"Joseph M. Newcomer" wrote:

If you are allocating them on the heap, with new, the easiest way is to add a
PostNcDestroy handler to your class whose body says
   delete this;
replacing the TODO: line.

You cannot delete an object earlier than the PostNcDestroy handler.
                                   joe

On Fri, 2 May 2008 10:59:01 -0700, Nick Schultz <NickSchu...@discussions.microsoft.com>
wrote:

Hi there,

My user will need to be able to open any number of graphing
windows(CDockablePane) in my application. When the window is closed, I want
the pane to be destroyed.

In order to do this I will have my window catch the press close button event
(CPane::OnPressCloseButton) and then have it call DestroyWindow().

reading DestroyWindow description, it looks like it does everything but it
does not destroy the CWnd object.

So how do I destroy the CWnd object? Do i just simply need to call delete
(pointer to graph window). I was thinking I could override the NotifyParent
function to catch child destroyed event and then deleting it then, however
the parent gets notified BEFORE any destruction takes place.

I'm not sure if this is possible, but after calling DestroyWindow() within
the OnPressCloseButton() function, could I just call "delete this" to free
up any memory used by the graph window?

Any suggestions are greatly appreciated.

Nick

Joseph M. Newcomer [MVP]
email: newco...@flounder.com
Web:http://www.flounder.com
MVP Tips:http://www.flounder.com/mvp_tips.htm


Dont call DestroyWindow; use PostMessage(WM_CLOSE) instead. See if
that helps.

--
Ajay

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