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QML Canvas Qt6 - Cannot assign to non-existent property "onPaint"

I'm working on a project in Qt6, utilizing Qt Design Studio.

I'm currently facing an issue related to a Canvas element in QML. Specifically, I'm trying to use the onPaint signal handler, but I encounter the following error:

Cannot assign to non-existent property "onPaint"

I've already ensured that I'm importing both QtQuick 2.15 and QtQuick.Controls 2.15. Below is the relevant code snippet:

import QtQuick 2.15
import QtQuick.Controls 2.15

...

Canvas {
    id: canvas
    anchors.fill: parent

    onPaint: {
        // Some code...
    }
}

Can anyone help me understand why I'm getting this error and how I can resolve it?

Additional info:

  • Qt Version: 6.4.0
  • Qt Design Studio Version: 3.9.0

EDIT 1:

As suggested, I have removed the version numbers from the imports, but the error still occurs.

New code:

import QtQuick
import QtQuick.Controls

Canvas {
    onPaint: {
        // Some code...
Solution

  • The Qt6.x documentation https://doc.qt.io/qt-6/qml-qtquick-canvas.html actually has a mistake. It should not include a version number in the import line imports:

    import QtQuick
Canvas {
    id: mycanvas
    width: 100
    height: 200
    onPaint: {
        var ctx = getContext("2d");
        ctx.fillStyle = Qt.rgba(1, 0, 0, 1);
        ctx.fillRect(0, 0, width, height);
    }
}

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