´QGraphicsView QGraphicsItem:不规模项目当缩放视图矩形

I am using Qt´s QGraphicsView- and QGraphicsItem-subclasses. is there a way to not scale the graphical representation of the item in the view when the view rectangle is changed, e.g. when zooming in. The default behaviour is that my items scale in relation to my view rectangle.I am using Qt´s QGraphicsView- and QGraphicsIte