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Unable to view rectangle(red color) drawn using Qpainter when the window background is set to black color



  • i want to draw a red color rectangle on a black backgrounded window but unable to view the rectangle. My code is as below:

    void MainWindow::paintEvent(QPaintEvent *e)
    {
    QPainter painter(this);

    QPen linepen(Qt::red);
    linepen.setWidth(5);

    painter.setPen(linepen);

    painter.drawRect(230,120,121,71);
    }


  • Lifetime Qt Champion

    Hi and welcome to devnet,

    The pen is used for the lines and outlines. If you want to have a rect in red, either use a red brush or use the fillRect function.



  • Using red brush or fillRect is making inner part of the rectangle also filled up with red color. I want only the border of the rectangle to be filled with red and inner part to be transparent.


  • Lifetime Qt Champion

    Then set the brush to Qt::transparent.


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