CWnd::DestroyWindow

Статья
10/16/2008

Destroys the Windows window attached to the CWnd object.

virtual BOOL DestroyWindow( );

Возвращаемое значение

Nonzero if the window is destroyed; otherwise 0.

Заметки

The DestroyWindow member function sends appropriate messages to the window to deactivate it and remove the input focus. It also destroys the window's menu, flushes the application queue, destroys outstanding timers, removes Clipboard ownership, and breaks the Clipboard-viewer chain if CWnd is at the top of the viewer chain. It sends WM_DESTROY and WM_NCDESTROY messages to the window. It does not destroy the CWnd object.

DestroyWindow is a place holder for performing cleanup. Because DestroyWindow is a virtual function, it is shown in any CWnd-derived class in Class View. But even if you override this function in your CWnd-derived class, DestroyWindow is not necessarily called. If DestroyWindow is not called in the MFC code, then you have to explicitly call it in your own code if you want it to be called.

Assume, for example, you have overridden DestroyWindow in a CView-derived class. Since MFC source code does not call DestroyWindow in any of its CFrameWnd-derived classes, your overridden DestroyWindow will not be called unless you call it explicitly.

If the window is the parent of any windows, these child windows are automatically destroyed when the parent window is destroyed. The DestroyWindow member function destroys child windows first and then the window itself.

The DestroyWindow member function also destroys modeless dialog boxes created by CDialog::Create.

If the CWnd being destroyed is a child window and does not have the WS_EX_NOPARENTNOTIFY style set, then the WM_PARENTNOTIFY message is sent to the parent.

Пример

// CModeless is a CDialog class representing a modeless dialog
// Destruction of the modeless dialog involves calling DestroyWindow in 
// OnOK() & OnCancel() handlers
void CModeless::OnOK() 
{ 
   if (!UpdateData(TRUE)) 
   {
      TRACE(_T("UpdateData failed during dialog termination\n"));
      // The UpdateData routine will set focus to correct item
      return;
   }
   DestroyWindow();
}

void CModeless::OnCancel()
{
   DestroyWindow();
}