QPainter::begin: Paint device returned engine == 0, type: 1

pufuzbufu

Hi everyone. I have a simple QPainter program and I received this error when I'm trying to paint a widget.

here is the code:
@void MyGraphicsView::paintEvent(QPaintEvent *event)
{
QPainter p(this);
p.setPen(Qt::red);
p.drawText(10,10,"some text");

}@

here you can download a small sample project in case you wanna test it yourself: http://www.box.net/shared/yitvqvfcdv

dangelog

Didn't download the snippet, but if that class is a subclass of a QGraphicsView (and in general of a QAbstractScrollArea), you need to paint on the viewport().

srikanth_trulyit

Try paint on the graphicsview'v viewport. GraphicsView will always paint its content to its viewport.

pufuzbufu

ok. thanks. that worked. However now I'm facing a similar problem:

I'm trying to render a QWebElement into a QWidget and I received the same error. here is my code:

@QPainter painter(this->imageWidget);
this->webElement.render(&painter);@

I receive the following errors:

bq. QPainter::begin: Paint device returned engine == 0, type: 1
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::setBrush: Painter not active
QPainter::pen: Painter not active
QPainter::setPen: Painter not active
QPainter::save: Painter not active
QPainter::translate: Painter not active
QPainter::save: Painter not active

astodolski

[quote author="pufuzbufu" date="1307012108"]Hi everyone. I have a simple QPainter program and I received this error when I'm trying to paint a widget.

here is the code:
@void MyGraphicsView::paintEvent(QPaintEvent *event)
{
QPainter p(this);
p.setPen(Qt::red);
p.drawText(10,10,"some text");

}@

here you can download a small sample project in case you wanna test it yourself: http://www.box.net/shared/yitvqvfcdv[/quote]

Downloaded, compiled, run. Draws nothing!

SGaist

Hi,

Why are you reviving a post that's more than 3 years old ?

astodolski

[quote author="SGaist" date="1409084983"]Hi,

Why are you reviving a post that's more than 3 years old ?[/quote]

It's in the context of a problem I searched. Still the sample linked doesn't work. Change the forum engine so it can't be commented on (reviving) if that's causing a problem.