当我将窗口移动到具有不同DPI的屏幕时，为什么我的QML项不能缩放？

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}

import QtQuick 2.15
import QtQuick.Window 2.15

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("High DPI Scaling Example")

    Component.onCompleted: {
        var screen = Screen.current;
        var dpi = screen.logicalDotsPerInch;
        // 根据DPI调整窗口大小或其他属性
        width = 640 * (dpi / 96);
        height = 480 * (dpi / 96);
    }
}