Cannot Use Applicationwindow (qml) On Pyside2

I'm trying to run a simple Qt application using QML and more specifically ApplicationWindow. My Python code is a simple QML caller: import sys from PySide2.QtWidgets import QApplic

Solution 1:

First, as pyside returns:

QQuickView does not support using windows as a root item. If you wish to create your root window from QML, consider using QQmlApplicationEngine instead.

This is a working example:

main.py

import sys
fromPySide2.QtWidgetsimport QApplication
fromPySide2.QtCoreimportQt, QCoreApplication
fromPySide2.QtQmlimport QQmlApplicationEngine

if __name__ == '__main__':

    app = QApplication(sys.argv)

    QApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
    QCoreApplication.setAttribute(Qt.AA_UseHighDpiPixmaps)

    engine = QQmlApplicationEngine('view.qml')

    sys.exit(app.exec_())

view.qml

importQtQuick.Controls2.4importQtQuick2.0ApplicationWindow {

    title:"Qt Quick Controls Gallery"visible:truewidth:640height:480Rectangle {
        width:30height:30color:"blue"
    }
}

Solution 2:

If you read the docs:

The QQuickView class provides a window for displaying a Qt Quick user interface.

That is, QQuickView provides a window to show Items, but ApplicationWindow is already a window so you do not need and should not use QQuickView anymore, in the case of ApplicationWindow you must use QQmlApplicationEngine:

main.py

import sys
from PySide2 import QtCore, QtGui, QtQml

if __name__ == '__main__':

    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QtGui.QGuiApplication(sys.argv)
    engine = QtQml.QQmlApplicationEngine()
    url = QtCore.QUrl.fromLocalFile('view.qml')
    engine.load(url)
    if not engine.rootObjects():
        sys.exit(-1)
    sys.exit(app.exec_())

view.qml

import QtQuick 2.7import QtQuick.Controls 2.4

ApplicationWindow {
    title: "Qt Quick Controls Gallery"
    width: 640
    height: 480
    visible: true// <---
}