Opacity with Qt

[Jordison67]

Hello.

I would like to change the opacity of a shape in a QgraphicsView by increasing the value in a variable white a horizontal slider but I can not do it. I tried with this code but it does not matter.


qreal opacity = 0.0;
shape->setOpacity(opacity);

Thank you. :)

[d_stranz]

You probably need to call QGraphicsView::invalidateScene() or QGraphicsView::update() after making the change. If your items are children of other items, you may also have to set opacity propagation flags ( see QGraphicsItem::setOpacity()):


There are two item flags that affect how the item's opacity is combined with the parent: ItemIgnoresParentOpacity and ItemDoesntPropagateOpacityToChildren.

[Jordison67]

Hello thank you very much but it does not help me much better with a small piece of code I will continue to search...