问题
I'm pretty new to QGraphicsView in Qt.
As far as I can tell there is no built in way to resize a QGraphicsItem in a scene with a mouse.
What I'm looking for is to be able to resize a QGraphicsRectItem by either dragging out the corners or the edges on screen.
Is there a simple way to do that? Is there a library or a piece of code somewhere online that implements this functionality?
I'm currently using Qt 4.5.1.
回答1:
I guess this thread has a similar question. You will have to manually resize the item after intercepting the mousemove events. You can get the 'pos' from 'event' argument like:-
QPointF pt = event->pos()
Use this point 'pt' for resizing to the correct location.
Also lookup the 'Elastic Nodes' application in Qt Demos application. This will help.
来源：https://stackoverflow.com/questions/1072047/qt-qgraphicsview-qgraphicsitem-resizing