使用QML文档库进行筛选(Qt Mobility)

我只想过滤一个艺术家的相册,但什么都不显示。

我的代码是:

选择ArtistPage.qml:

import QtQuick 1.1
import com.nokia.meego 1.0
import QtMobility.gallery 1.1

Page
{
    id: selectArtistPage
    tools: backtoolbar
    property string selectedartist

    ListView
    {
        id: galleryView
        anchors.fill: parent
        clip: true
        model: artistModel
        delegate: Item
        {
            height: 60
            width: parent.width
            Button
            {
                height: 50
                width: parent.width - 20
                text: (artist != "") ? artist : "(unknown artist)"
                onClicked:
                {
                    selectedartist = (text != "(unknown artist)") ? text : ""
                    selectAlbumPageLoader.source = "SelectAlbumPage.qml"
                    pageStack.push(selectAlbumPageLoader.item)
                }
            }
        }
    }

    DocumentGalleryModel
    {
        id: artistModel
        rootType: DocumentGallery.Artist
        properties: ["artist"]
    }
}

选择相册页面.qml:

import QtQuick 1.1
import com.nokia.meego 1.0
import QtMobility.gallery 1.1

Page
{
    id: selectAlbumPage
    tools: backtoolbar
    property string selectedalbum

    ListView
    {
        id: galleryView
        anchors.fill: parent
        clip: true
        model: albumModel
        delegate: Item
        {
            height: 60
            width: parent.width
            Button
            {
                height: 50
                width: parent.width - 20
                text: (albumTitle != "") ? albumTitle : "(unknown album)"
                onClicked:
                {
                    selectedalbum = (text != "(unknown album)") ? text : ""
                    // here should be launching the last page
                }
            }
        }
    }

    DocumentGalleryModel
    {
        id: albumModel
        rootType: DocumentGallery.Album
        properties: ["albumTitle", "artist"]
        filter: GalleryEqualsFilter
        {
            property: "artist"
            value: selectedartist
        }
    }
}

当我在SelectArtistPage中选择艺术家时,会打开另一个页面,不会绘制带有相册名称的按钮。 如果我删除过滤器,所有相册都会显示出来。

我做错了什么?我正在为Maemo使用Qt Mobility 1.2软件包(我正在N900上测试)。