How to set the QGraphicsWidget transparent, but the controls on it not transparent?

[opengpu]

i set the QGraphicsWidget transparent by setOpacity,
then i add QGraphicsProxyWidget and QWidget on it, and i tried set these controls on the QGraphicsWidget not transparent by setOpacity/setWindowOpacity...but it does not work,
so how to set there child controls on QGraphicsWidget not transparent while keeping the QGraphicsWidget transparent?

[opengpu]

waitting...