QWidget旋转

https://stackoverflow.com/questions/43388464/rotate-whole-qwidget-by-angle

QGraphicsScene* scene = new QGraphicsScene(this);
QPushButton* button = new QPushButton();
button->setText(“My cool button”);

QGraphicsProxyWidget* w = scene->addWidget(button);
w->setPos(50, 50);
w->setRotation(45);
ui->graphicsView->setScene(scene);