[SOLVED]Graphicsview how to

[toho71]

Hello
I'm trying to use the graphicsview and graphics scene.
Only a simpel test to build from but even this doesn't work

I use qt desigener and puts the g_view on the mainwindow and I'm trying to set the scene in the constructor.

But nothing happens.
Here is some code.

@m_graphScen = new QGraphicsScene(this);
m_graphScen->setSceneRect(0,0,790,290);
m_graphScen->addText("Hello, world!");
// a blue background
m_graphScen->setBackgroundBrush(Qt::blue);

// a gradient background
QRadialGradient gradient(0, 0, 10);
gradient.setSpread(QGradient::RepeatSpread);
m_graphScen->setBackgroundBrush(gradient);

QPainterPath path;
path.moveTo(10, 30);
path.cubicTo(80, 0, 50, 50, 80, 80);

m_graphScen->addPath(path, QPen(Qt::black), QBrush(Qt::green));

m_graphScen->addText("Hello, world!", QFont("Times", 10, QFont::Bold));


ui->m_graphView->setFixedSize(800,300);
ui->m_graphView->setScene(m_graphScen);
ui->m_graphView->setBackgroundBrush(Qt::blue);

@

The problem wasn't here.
It was the calling to this method that was the problem