QWidget *hideQw;//QWidget 指针
hideQw=ui->tabWidget->widget(3);//指针指向要隐藏的一页
//Removes the tab at position index from this stack of widgets. The page widget itself //is not deleted. ui->tabWidget->removeTab(3);//删除该页,实际该页还在
ui->tabWidget->addTab(hideQw,"隐藏页");//想要重新显示