QPixmap: Must construct a QGuiApplication before a QPixmap after copying a picture to clipboard

[WolleKette]

Hi at all,

I want to take a screenshot in my application and copy it to the clipboard. This also works. But when I've done that at least once, I get an error and python crashes when I close the application.

QPixmap: Must construct a QGuiApplication before a QPixmap

I have already found many posts about the above error message on the Internet, but unfortunately no solution yet. I use PySide6 - 6.2.3 on a Mac.

Here is a small example to reproduce the problem.

import sys
from PySide6.QtWidgets import QApplication, QWidget, QPushButton, QMessageBox

class MainWindow(QWidget):
    def __init__(self):
        super().__init__()

        btn_screenshot = QPushButton('Take screenshot to clipboard', self)
        btn_screenshot.clicked.connect(self.take_screenshot)
        btn_screenshot.move(50, 50)

        self.setGeometry(100, 100, 300, 150)
        self.setWindowTitle('Window Example')

        self.show()


    def take_screenshot(self):
        p = self.grab()
        clipboard = QApplication.clipboard()
        clipboard.setPixmap(p)

        QMessageBox.information(self, 'Message', 'Screenshot is copied to clipboard', QMessageBox.Ok)


app = QApplication(sys.argv)
ex = MainWindow()
sys.exit(app.exec_())

[WolleKette]

@SGaist
No, if I convert the QPixmap to a QImage, then it works without problems. Also under the older PySide6 version. Here is the code if someone has the same problem...

        pixmap = self.grab()
        image = pixmap.toImage()

        clipboard = QApplication.clipboard()
        clipboard.setImage(image)

[SGaist]

Hi,

How did you install PySide6 ?
On which version of macOS ?
Can you try with a more recent version of PySide6 ?

[WolleKette]

@SGaist said in QPixmap: Must construct a QGuiApplication before a QPixmap after copying a picture to clipboard:

Can you try with a more recent version of PySide6 ?

No problem thanks to virtual environments. In Version 6.5.1.1, the error message has changed to

qt.qpa.clipboard: Cannot keep promise, data contains QPixmap and requires livining QGuiApplication

I use macOS Ventura 13.4.1. While I'm at it, I also tested it on Windows (10). There it runs without error message.

[SGaist]

Do you have the same issue if you change your pixmap to a QImage and use setImage in place ?

[WolleKette]

@SGaist
No, if I convert the QPixmap to a QImage, then it works without problems. Also under the older PySide6 version. Here is the code if someone has the same problem...

        pixmap = self.grab()
        image = pixmap.toImage()

        clipboard = QApplication.clipboard()
        clipboard.setImage(image)