问QT Quick XmlListModel仍然是空的

EN

import QtQuick 2.11
import QtQuick.Window 2.11
import QtQuick.XmlListModel 2.0

Window {
    visible: true
    width: 640
    height: 480

    XmlListModel {
        id: videoListModel
        source: "https://www.youtube.com/feeds/videos.xml?channel_id=UCupvZG-5ko_eiXAupbDfxWw"
        query: "/feed/entry"
        XmlRole { name: "title"; query: "title/string()" }
    }

    ListView {
        orientation: ListView.Vertical
        anchors.top: parent.top

        model: videoListModel

        delegate: Component {
            id: videoDelegate
            Text {
                text: title
                width: 200
                height: 50
            }
        }
    }
}