使用Phonon编程时，出现一下问题（我在.pro文件中已加入Qt +=qphonon)

[我们即将毕业了]

mainwindow.o: In function `MainWindow::closeEvent(QCloseEvent*)':
mainwindow.cpp:(.text+0xb31): undefined reference to `Phonon::MediaObject::stop()'
mainwindow.cpp:(.text+0xb3c): undefined reference to `Phonon::MediaObject::clearQueue()'
mainwindow.o: In function `MainWindow::playTrack(QTreeWidgetItem*)':
mainwindow.cpp:(.text+0xcbe): undefined reference to `Phonon::MediaObject::clearQueue()'
mainwindow.cpp:(.text+0xcce): undefined reference to `Phonon::MediaSource::MediaSource(QString const&)'
mainwindow.cpp:(.text+0xcdd): undefined reference to `Phonon::MediaObject::setCurrentSource(Phonon::MediaSource const&)'
mainwindow.cpp:(.text+0xce5): undefined reference to `Phonon::MediaSource::~MediaSource()'
mainwindow.cpp:(.text+0xcf0): undefined reference to `Phonon::MediaObject::play()'
mainwindow.cpp:(.text+0xdd6): undefined reference to `AQP::warning(QWidget*, QString const&, QString const&, QString const&)'
mainwindow.cpp:(.text+0xec1): undefined reference to `Phonon::MediaSource::~MediaSource()'
mainwindow.o: In function `MainWindow::playOrPause()':
mainwindow.cpp:(.text+0xeef): undefined reference to `Phonon::MediaObject::state() const'
mainwindow.cpp:(.text+0xf27): undefined reference to `Phonon::MediaObject::pause()'
mainwindow.cpp:(.text+0xf4f): undefined reference to `Phonon::MediaObject::play()'
mainwindow.o: In function `MainWindow::stop()':
mainwindow.cpp:(.text+0x11db): undefined reference to `Phonon::MediaObject::stop()'
mainwindow.cpp:(.text+0x11e6): undefined reference to `Phonon::MediaObject::clearQueue()'
mainwindow.o: In function `MainWindow::stateChanged(Phonon::State)':
mainwindow.cpp:(.text+0x12eb): undefined reference to `Phonon::MediaObject::errorString() const'
mainwindow.cpp:(.text+0x1331): undefined reference to `AQP::warning(QWidget*, QString const&, QString const&, QString const&)'
mainwindow.o: In function `MainWindow::aboutToFinish()':
mainwindow.cpp:(.text+0x1543): undefined reference to `Phonon::MediaSource::MediaSource(QString const&)'
mainwindow.cpp:(.text+0x1552): undefined reference to `Phonon::MediaObject::enqueue(Phonon::MediaSource const&)'
mainwindow.cpp:(.text+0x155a): undefined reference to `Phonon::MediaSource::~MediaSource()'
mainwindow.cpp:(.text+0x1788): undefined reference to `Phonon::MediaSource::~MediaSource()'
mainwindow.o: In function `MainWindow::minutesSecondsAsStringForMSec(long long)':
mainwindow.cpp:(.text+0x17e3): undefined reference to `AQP::hoursMinutesSecondsForMSec(int, int*, int*, int*)'
mainwindow.o: In function `MainWindow::waitForMediaObjectToLoad(Phonon::MediaObject*, int)':
mainwindow.cpp:(.text+0x1a43): undefined reference to `Phonon::MediaObject::state() const'
mainwindow.o: In function `MainWindow::createWidgets()':
mainwindow.cpp:(.text+0x1ab4): undefined reference to `Phonon::SeekSlider::SeekSlider(QWidget*)'
mainwindow.cpp:(.text+0x1b19): undefined reference to `Phonon::SeekSlider::setMediaObject(Phonon::MediaObject*)'
mainwindow.cpp:(.text+0x1b33): undefined reference to `Phonon::VolumeSlider::VolumeSlider(QWidget*)'
mainwindow.cpp:(.text+0x1b98): undefined reference to `Phonon::VolumeSlider::setAudioOutput(Phonon::AudioOutput*)'
mainwindow.o: In function `MainWindow::MainWindow(QWidget*)':
mainwindow.cpp:(.text+0x2087): undefined reference to `Phonon::MediaObject::MediaObject(QObject*)'
mainwindow.cpp:(.text+0x209a): undefined reference to `Phonon::MediaObject::setTickInterval(int)'
mainwindow.cpp:(.text+0x20bc): undefined reference to `Phonon::AudioOutput::AudioOutput(Phonon::Category, QObject*)'
mainwindow.cpp:(.text+0x20ee): undefined reference to `Phonon::createPath(Phonon::MediaNode*, Phonon::MediaNode*)'
mainwindow.cpp:(.text+0x20f9): undefined reference to `Phonon::Path::~Path()'
mainwindow.o: In function `MainWindow::addTrack(QString const&, QHash<QString, TreeWidgetItem*>*, QHash<QString, TreeWidgetItem*>*)':
mainwindow.cpp:(.text+0x226e): undefined reference to `Phonon::MediaObject::MediaObject(QObject*)'
mainwindow.cpp:(.text+0x2281): undefined reference to `Phonon::MediaSource::MediaSource(QString const&)'
mainwindow.cpp:(.text+0x228d): undefined reference to `Phonon::MediaObject::setCurrentSource(Phonon::MediaSource const&)'
mainwindow.cpp:(.text+0x22e0): undefined reference to `Phonon::MediaObject::metaData(Phonon::MetaData) const'
mainwindow.cpp:(.text+0x2377): undefined reference to `Phonon::MediaObject::metaData(Phonon::MetaData) const'
mainwindow.cpp:(.text+0x24c2): undefined reference to `Phonon::MediaObject::metaData(Phonon::MetaData) const'
mainwindow.cpp:(.text+0x253a): undefined reference to `Phonon::MediaObject::totalTime() const'
mainwindow.cpp:(.text+0x29ac): undefined reference to `Phonon::MediaSource::~MediaSource()'
mainwindow.cpp:(.text+0x29b4): undefined reference to `Phonon::MediaObject::~MediaObject()'
mainwindow.cpp:(.text+0x2cf4): undefined reference to `Phonon::MediaSource::~MediaSource()'
mainwindow.cpp:(.text+0x2cfc): undefined reference to `Phonon::MediaObject::~MediaObject()'
mainwindow.o: In function `MainWindow::getSuffixes()':
mainwindow.cpp:(.text+0x2f79): undefined reference to `Phonon::BackendCapabilities::availableMimeTypes()'
mainwindow.cpp:(.text+0x3018): undefined reference to `AQP::suffixesForMimeTypes(QStringList const&)'
collect2: ld 返回 1

[雲天之巔]

说明你的phonon库没有编译。

[我们即将毕业了]

怎么编译phonon库，我已经安装Qt包了