How can I draw a png image using QPixmap and QPainter?

sofiane

I'm trying to draw an image into my widget window, what is the right way of doing, the following code is not displaying anything on the window :

#include <QCoreApplication>
#include <QApplication>
#include <QWidget>
#include <QPainter>
#include <QColor>
#include <QRectF>
#include <QPicture>

class Win: public QWidget{
public:
    void paintEvent(QPaintEvent *){
        QPainter painter(this);

        QRectF target(10.0, 20.0, 800.0, 600.0);
        QRectF source(0.0, 0.0, 400.0, 400.0);
        QPixmap pixmap("qrc:/browser_web_internet_website.png");

        painter.drawPixmap(target, pixmap, source);
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Win *win = new Win();

    win->show();
    return a.exec();
}

SGaist

QLabel

SGaist

Hi,

Check that your pixmap is valid.

sofiane

@SGaist What do you mean by valid? the image exists, what I mean by not working is that the window opens but not displaying anything.

sofiane

@SGaist It worked when I removed the qrc/, I wonder why, I always worked with qrc:/filename.png, now it required only :filename.png?

SGaist

No, it's always been ":/". AFAR, qrc:/ is used in QML and when using QUrl.

sofiane

@SGaist sorry for reopening the issue, I wanted to add a picture to a pre-existing QWidget object, is it possible to do that ? this method requires creating another class which inherits from qwidget, and implement the paintEvent, but I just want to add a picture to an already existing qwidget window.

SGaist

QLabel