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Mediensitzung implementieren

Erstellen Sie eine MediaSession , wenn Ihre App die Wiedergabe von Medien vorbereitet. Das folgende Code-Snippet ist ein Beispiel dafür, wie Sie den entsprechenden Callback und die entsprechenden Flags festlegen:

Kotlin

session = MediaSession(this, "MusicService").apply {
    setCallback(MediaSessionCallback())
    setFlags(
        MediaSession.FLAG_HANDLES_MEDIA_BUTTONS or MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS
    )
}MediaSession.kt

Java

session = new MediaSession(this, "MusicService");
session.setCallback(new MediaSessionCallback());
session.setFlags(MediaSession.FLAG_HANDLES_MEDIA_BUTTONS |
        MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS);

Media Session starten

Rufen Sie beim Start der Wiedergabe auch setActive(true) auf. Ihre App muss außerdem den Audiofokus anfordern, wie unter Audiofokus verwalten beschrieben. Diese Schritte werden im folgenden Beispiel gezeigt:

Kotlin

fun handlePlayRequest() {
    tryToGetAudioFocus()

    if (!session.isActive) {
        session.isActive = true
    }
    // ...
}MediaSession.kt

Java

private void handlePlayRequest() {

    tryToGetAudioFocus();

    if (!session.isActive()) {
        session.setActive(true);
    }
    ...
}

Wiedergabestatus aktualisieren

Aktualisieren Sie den Wiedergabestatus in der MediaSession, um den Status der aktuellen Medien widerzuspiegeln:

Kotlin

private fun updatePlaybackState() {
    val position: Long =
        mediaPlayer
            ?.takeIf { it.isPlaying }
            ?.currentPosition?.toLong()
            ?: PlaybackState.PLAYBACK_POSITION_UNKNOWN

    val stateBuilder = PlaybackState.Builder()
        .setActions(getAvailableActions()).apply {
            setState(mState, position, 1.0f)
        }
    session.setPlaybackState(stateBuilder.build())
}

private fun getAvailableActions(): Long {
    var actions = (
        PlaybackState.ACTION_PLAY_PAUSE
            or PlaybackState.ACTION_PLAY_FROM_MEDIA_ID
            or PlaybackState.ACTION_PLAY_FROM_SEARCH
        )

    playingQueue?.takeIf { it.isNotEmpty() }?.apply {
        actions = if (mState == PlaybackState.STATE_PLAYING) {
            actions or PlaybackState.ACTION_PAUSE
        } else {
            actions or PlaybackState.ACTION_PLAY
        }
        if (currentIndexOnQueue > 0) {
            actions = actions or PlaybackState.ACTION_SKIP_TO_PREVIOUS
        }
        if (currentIndexOnQueue < size - 1) {
            actions = actions or PlaybackState.ACTION_SKIP_TO_NEXT
        }
    }
    return actions
}MediaSession.kt

Java

private void updatePlaybackState() {
    long position = PlaybackState.PLAYBACK_POSITION_UNKNOWN;
    if (mediaPlayer != null && mediaPlayer.isPlaying()) {
        position = mediaPlayer.getCurrentPosition();
    }
    PlaybackState.Builder stateBuilder = new PlaybackState.Builder()
            .setActions(getAvailableActions());
    stateBuilder.setState(mState, position, 1.0f);
    session.setPlaybackState(stateBuilder.build());
}

private long getAvailableActions() {
    long actions = PlaybackState.ACTION_PLAY_PAUSE |
            PlaybackState.ACTION_PLAY_FROM_MEDIA_ID |
            PlaybackState.ACTION_PLAY_FROM_SEARCH;
    if (playingQueue == null || playingQueue.isEmpty()) {
        return actions;
    }
    if (mState == PlaybackState.STATE_PLAYING) {
        actions |= PlaybackState.ACTION_PAUSE;
    } else {
        actions |= PlaybackState.ACTION_PLAY;
    }
    if (currentIndexOnQueue > 0) {
        actions |= PlaybackState.ACTION_SKIP_TO_PREVIOUS;
    }
    if (currentIndexOnQueue < playingQueue.size() - 1) {
        actions |= PlaybackState.ACTION_SKIP_TO_NEXT;
    }
    return actions;
}

Medienmetadaten aktualisieren

Legen Sie die MediaMetadata mit der setMetadata() Methode fest. Diese Methode wird nur einmal pro wiedergegebenem Objekt aufgerufen. So können Sie der Media Session Informationen zu den Medien zur Verfügung stellen, z. B. Titel, Untertitel, Künstler und Cover. Das folgende Beispiel ist auf Musik zugeschnitten und geht davon aus, dass die Daten des Titels in einer benutzerdefinierten Datenklasse MediaData gespeichert sind:

Kotlin

private fun updateMetadata(myData: MediaData) {
    val metadataBuilder = MediaMetadata.Builder().apply {
        // To provide most control over how an item is displayed set the
        // display fields in the metadata
        putString(MediaMetadata.METADATA_KEY_DISPLAY_TITLE, myData.displayTitle)
        putString(MediaMetadata.METADATA_KEY_DISPLAY_SUBTITLE, myData.displaySubtitle)
        putString(MediaMetadata.METADATA_KEY_DISPLAY_ICON_URI, myData.artUri)
        // And at minimum the title and artist for legacy support
        putString(MediaMetadata.METADATA_KEY_TITLE, myData.title)
        putString(MediaMetadata.METADATA_KEY_ARTIST, myData.artist)
        // A small bitmap for the artwork is also recommended
        putBitmap(MediaMetadata.METADATA_KEY_ART, myData.artBitmap)
        // Add any other fields you have for your data as well
    }
    session.setMetadata(metadataBuilder.build())
}MediaSession.kt

Java

private void updateMetadata(MediaData myData) {
    MediaMetadata.Builder metadataBuilder = new MediaMetadata.Builder();
    // To provide most control over how an item is displayed set the
    // display fields in the metadata
    metadataBuilder.putString(MediaMetadata.METADATA_KEY_DISPLAY_TITLE,
            myData.displayTitle);
    metadataBuilder.putString(MediaMetadata.METADATA_KEY_DISPLAY_SUBTITLE,
            myData.displaySubtitle);
    metadataBuilder.putString(MediaMetadata.METADATA_KEY_DISPLAY_ICON_URI,
            myData.artUri);
    // And at minimum the title and artist for legacy support
    metadataBuilder.putString(MediaMetadata.METADATA_KEY_TITLE,
            myData.title);
    metadataBuilder.putString(MediaMetadata.METADATA_KEY_ARTIST,
            myData.artist);
    // A small bitmap for the artwork is also recommended
    metadataBuilder.putBitmap(MediaMetadata.METADATA_KEY_ART,
            myData.artBitmap);
    // Add any other fields you have for your data as well
    session.setMetadata(metadataBuilder.build());
}