No effect of Qt::NoPen in QPainter

[beecksche]

Hi,
i want to disable the pen in my paintEvent function.

void PaintWidget::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);
    painter.translate(width() / 2.0, height() / 2.0);
    painter.setPen(Qt::NoPen);

    for (auto poly : m_poliygons)
    {
        painter.setBrush(QBrush(poly .color()));
        painter.drawPolygon(poly.polygon());
    }
}

But the outlines of the polygons are still painted.

Can someone help?

[mrjj]

Hi
Works in Qt 5.7 on win 10.
image url)

void MainWindow::on_pushButton_2_released()
{

    int h = ui->label->height();
    int w = ui->label->width();

    QPixmap pix(w, h);
    QPainter painter(&pix);
    pix.fill( Qt::white );
    QPolygon poly;

       poly << QPoint(0, 85) << QPoint(75, 75)
            << QPoint(100, 10) << QPoint(125, 75)
            << QPoint(200, 85) << QPoint(150, 125)
            << QPoint(160, 190) << QPoint(100, 150)
            << QPoint(40, 190) << QPoint(50, 125)\
            << QPoint(0, 85);

       //QPen pen(Qt::red, 3, Qt::DashDotLine, Qt::RoundCap, Qt::RoundJoin);
       painter.setPen(Qt::NoPen);
       painter.setBrush(QBrush(Qt::HorPattern));
       painter.drawPolygon(poly);

       ui->label->setPixmap(pix);

}

with pen..

[beecksche]

@mrjj
strange,
i'm using the new Qt 5.8.0 MSVC2013, but i don't think that's the reason.

[mrjj]

@beecksche

well try my code and see.
If still Pen it might be bug :)

[beecksche]

@mrjj
So i found the error:

I have to disable antialiasing:

painter.setRenderHint(QPainter::Antialiasing, false);

[mrjj]

@beecksche

ahahah :)
so it was not a real pen at all.
Good catch.

Please flag as Solved if possible.