Assert Modal Dialog wincore.cpp

[zqueezy]

hey folks, i stumbled across an assertion in my program. When I want to show a dialog modally the dialog is shown correctly, but when I close the dialog I get an assert: "Debug assertion failed! ... program ...wincore.cpp line 882" which is:

void CWnd::AssertValid() const
{
if (m_hWnd == NULL)
return; // null (unattached) windows are valid

// check for special wnd??? values
ASSERT(HWND\_TOP == NULL);       // same as desktop
if (m\_hWnd == HWND\_BOTTOM)
	ASSERT(this == &CWnd::wndBottom);
else if (m\_hWnd == HWND\_TOPMOST)
	ASSERT(this == &CWnd::wndTopMost);
else if (m\_hWnd == HWND\_NOTOPMOST)
	ASSERT(this == &CWnd::wndNoTopMost);
else
{
	// should be a normal window
	ASSERT(::IsWindow(m\_hWnd));    //<-- HERE

My code is farely simple:

CSelectionDlg dlg;
dlg.DoModal();

the thing is: I call this from a member-class:

-MyDialogDlg my dialog
-SomeClass m_instanceOfClass; a memberclass of dialog.
a function of Someclass does the above code

I found some stuff from microsoft: http://support.microsoft.com/kb/194300/eng which didn't work for my case! if I add

ASSERT(::IsWindow(m_hWnd));

before the domodal nothing changes... so somehow my handle gets lost and I donnu what to do. can anybody help? maybe a simple link. i tried many links, although nothing worked for my case. I don't have any crazy stuff in my OnInit of the dialog nor do I have another dialog as model dialog thx for your help zqueezy

[Hamid Taebi]

Did you try to trace your code line to line it seems you have a unvalid hwnd on your code.

[zqueezy]

well, as I said, the handle is valid before the DoModal-call! but somehow not during it

[Roger Broomfield]

I would expect your ASSERT placed before the DoModal() to succeed, it just means that you are calling DoModal() from a CWnd derived class that has a valid Window, it has no bearing on the state of the dialog. Are you calling DestroyWindow() somewhere in your Dialog class?