android - 从最近的应用程序中删除应用程序时取消前景通知

Question

我正在制作音乐播放器应用程序，我为音乐播放过程启动前台服务。但是当应用程序从最近的应用程序中删除时前景通知被取消，音乐仍在播放！ ，这意味着没有通知的前台服务。我尝试过：setAutoCancel(false)和setOnGoing(true)在创建NotificationCompat.Builder inctance时都没有用。

我的通知创建代码

public class MediaStyleHelper {
public static final String CHANNEL_ID = "2229";
public static NotificationCompat.Builder from(
        Context context, MediaSessionCompat mediaSession) {
    MediaControllerCompat controller = mediaSession.getController();
    MediaMetadataCompat mediaMetadata = controller.getMetadata();
    MediaDescriptionCompat description = mediaMetadata.getDescription();

    NotificationCompat.Builder builder = new NotificationCompat.Builder(context , CHANNEL_ID);
    builder
            .setContentTitle(description.getTitle())
            .setContentText(description.getSubtitle())
            .setSubText(description.getDescription())
            .setLargeIcon(description.getIconBitmap())
            .setContentIntent(controller.getSessionActivity())
            .setDeleteIntent(
                    MediaButtonReceiver.buildMediaButtonPendingIntent(context, PlaybackStateCompat.ACTION_STOP))
            .setAutoCancel(false)
            .setVisibility(NotificationCompat.VISIBILITY_PUBLIC);

    return builder;
}

}

清单中的服务：

<service android:name=".services.AudioPlayerService"
        android:exported="false"
        android:enabled="true">
        <intent-filter>
            <action android:name="android.intent.action.MEDIA_BUTTON" />
            <action android:name="android.media.AUDIO_BECOMING_NOISY" />
            <action android:name="android.media.browse.MediaBrowserService" />
        </intent-filter>
    </service>

并启动前台代码

private void showPlayingNotification() {
    NotificationCompat.Builder builder = MediaStyleHelper.from(this, mMediaSessionCompat);
    if( builder == null ) {
        return;
    }

    builder.addAction(new NotificationCompat.Action(android.R.drawable.ic_media_pause, getString(R.string.pause), MediaButtonReceiver.buildMediaButtonPendingIntent(this, PlaybackStateCompat.ACTION_PLAY_PAUSE)));
    builder.setStyle(new androidx.media.app.NotificationCompat.MediaStyle().setShowActionsInCompactView(0).setMediaSession(mMediaSessionCompat.getSessionToken()));
    builder.setSmallIcon(R.drawable.ic_play_circle_outline);
    builder.setOngoing(true);
    startForeground(1,builder.build());
    //NotificationManagerCompat.from(AudioPlayerService.this).notify(1, builder.build());
}

请注意我使用代码创建了通知通道：

private void createNotificationChannel() {
    // Create the NotificationChannel, but only on API 26+ because
    // the NotificationChannel class is new and not in the support library
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        CharSequence name = getString(R.string.channel_name);
        String description = getString(R.string.channel_description);
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
        channel.setDescription(description);
        channel.setSound(null,null);
        // Register the channel with the system; you can't change the importance
        // or other notification behaviors after this
        NotificationManager notificationManager = getSystemService(NotificationManager.class);
        notificationManager.createNotificationChannel(channel);
    }
}

Answer 1

解决方案是从活动中调用startService(Intent)。即使我打电话给MediaBrowserCompat.connect()和媒体播放正确，我需要打电话给startService(Intent)！编辑后的代码是：

public void initMediaBrowserCompat(){
    startService(new Intent(this,AudioPlayerService.class));
    mMediaBrowserCompat = new MediaBrowserCompat(this, new ComponentName(this, AudioPlayerService.class),
            mMediaBrowserCompatConnectionCallback, getIntent().getExtras());
    mMediaBrowserCompat.connect();

}