如何隐藏QDockWidget的标题栏

http://www.qtforum.org/article/32788/can-a-qdockwidget-titlebar-be-hidden.html

看起来很靠谱但是不好用――QDockWidget总是会创建一个标题栏

QWidget * titleBarWidget = dockWidget->titleBarWidget();
dockWidget->setTitleBarWidget( NULL );
delete titleBarWidget;

这是可以用的――

QWidget* lTitleBar = mDock->titleBarWidget();
QWidget* lEmptyWidget = new QWidget();
mDock->setTitleBarWidget(lEmptyWidget);
delete lTitleBar;