Re: Access violation on calling GetSafeHwnd()

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>
Wed, 28 Feb 2007 09:47:40 -0500
Testkr wrote:

Hi Scott,

Here is the piece of code -

BOOL CZedObjectFrame::OnCmdMsg( UINT nID, int nCode, void * pExtra,
   // call up, does menu and toolbar updates
   BOOL rc = FALSE;

   if (!CanUserModify() && m_pToolBar != NULL)
      CToolBarCtrl & ctrlFramework = m_pToolBar->GetToolBarCtrl();
      if(ctrlFramework.IsButtonEnabled(nID) == 0)
         return rc;

   rc = CFrameWnd::OnCmdMsg(nID, nCode, pExtra, pHandlerInfo);

access violation here >>>> HWND viewHandle = GetSafeHwnd();
   if(viewHandle != NULL && ::IsWindow(viewHandle))

Get a breakpoint there. (You may need to add some temporary code so it
breaks on the relevant message.) When it hits the breakpoint examine
the 'this' pointer, and its member variables, to see what you've got. I
don't see any way it could fail unless 'this' is corrupt. Keep in mind
that a lot of stuff is executed when you call CFrameWnd::OnCmdMsg, so
something in there may be causing mayhem. You could move the
troublesome line ahead of the call to see if that changes things.

Scott McPhillips [VC++ MVP]

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