void QMainWindow::tabifyDockWidget ( QDockWidget * first, QDockWidget * second )
Moves second dock widget on top of first dock widget, creating a tabbed docked area in the main window.
See also tabifiedDockWidgets().
只是现在好像还不能在Qt designer 中直接生成tab的DockWidget,也可能是我不会,有知道的告我一声,谢谢