Using a QGraphicsView Widget

[Mister Rose]

Maybe I am not following the correct workflow, but this has worked on other elements.

I am using Qt Creator 3.6.1, which has Qt 5.6.0 MSVC 2013 on a Windows PC.

I added a QGraphicsView widget to the Window form, and I want to draw a rectangle in it.

In the form's constructor, I put the following code, the last line of which causes a segmentation fault. Note that the rect is a data member of the Form's class. (The first line was already there).

ui->setupUi(this);
rect.setRect(10,10,20,30);
ui->graphicsView->scene()->addItem(&rect);

I also tried putting the rect on the heap like this.

rect = new QGraphicsRectItem(10,10,20,30);
ui->graphicsView->scene()->addItem(rect);

Same problem. The Segfault occurs in the addItem call.

Does the scene need to be allocated? I don't see a setScene method, so I assumed that the framework initialized everything.

Thoughts?

[A Former User]

@Mister-Rose Hi! Yes, you need to create the scene, too, and give it to the view:

QGraphicsScene *scene = new QGraphicsScene(this);
ui->graphicsView->setScene(scene);

[A Former User]

@Mister-Rose Hi! Yes, you need to create the scene, too, and give it to the view:

QGraphicsScene *scene = new QGraphicsScene(this);
ui->graphicsView->setScene(scene);

[Mister Rose]

@Wieland said in Using a QGraphicsView Widget:

ui->graphicsView->setScene(scene);

Thank you. Works as expected.