title: QT How to remove the action menu item
body: <p>when i add the widget to the main window, by default the action menu item will be present,
  how to remove that?</p>
  
  <pre><code>menuBar()-&gt;setVisible(false);
  
  verAction = new QAction(tr("&amp;Version"),this);
  menuBar()-&gt;addAction(verAction);
  connect(verAction, SIGNAL(triggered()),this, SLOT(displayVersion()));
  
  displayAction = new QAction(tr("&amp;Display"),this);
  menuBar()-&gt;addAction(displayAction);
  
  
   connect(displayAction, SIGNAL(triggered()),this, SLOT(displayMessage()));
  
  exitAction = new QAction(tr("&amp;Exit"),this);
  menuBar()-&gt;addAction(exitAction);
  connect(exitAction, SIGNAL(triggered()),this, SLOT(close()));
  </code></pre>
  
  <p>Thanks</p>