自定义QML QQuickPainted项成员锚点在qml中未设置为父项

import QtQuick 2.15

Rectangle {
    width: 640
    height: 480
    color: "lightgray"

    // 自定义绘制项
    MyCustomPaintedItem {
        id: customItem
        anchors.centerIn: parent // 设置为中心对齐
        width: 100
        height: 100
    }
}

// 自定义 QQuickPaintedItem
QtObject {
    id: myCustomPaintedItem

    property Component customItemComponent: Component {
        QQuickPaintedItem {
            onPaint: {
                var ctx = getContext("2d");
                ctx.fillStyle = "blue";
                ctx.fillRect(0, 0, width, height);
            }
        }
    }

    Component.onCompleted: {
        var item = customItemComponent.createObject(parent);
        item.anchors.fill = parent; // 确保锚点填充父项
    }
}