我花了大约20个小时到现在，我的问题仍然存在。 我正在创建一个具有多个活动的android应用程序（mainMenu，aboutUs，setting）。 我按照下面链接的最佳答案，那是O.K。 Music played using asyncTask isn't stopping by using cancel
当我运行我的应用程序时，（我的代码在mainActivity中），音乐开始并且在导航到其他活动时不会停止。这很好。 但我在我的setting_activity活动中放了一个 ToggleButton ，我希望这个按钮启动并停止播放音乐。现在我的问题是如何从setting_activity中再次停止和/或启动音乐？
在另一个解决方案中： 我创建了一个类MusicManager，我称之为开始和停止。 但这也是几个问题：
我无法停止来自其他活动的音乐。这次我在mainMenua_ctivity中播放音乐作为此行代码：
MusicManager mm = new MusicManager(this, R.raw.background_sound);
mm.play();
我怎么能停止播放？ 当我导航到其他活动时，音乐停止了。
public class MusicManager implements OnPreparedListener {
static MediaPlayer mPlayer;
Context context;
private int mySoundId;
public MusicManager(Context ctx, int musicID) {
context = ctx;
mySoundId = musicID;
mPlayer = MediaPlayer.create(context, mySoundId);
mPlayer.setOnPreparedListener(this);
}
public void play() {
mPlayer = MediaPlayer.create(context, mySoundId);
}
public void stop() {
mPlayer.stop();
mPlayer.release();
}
@Override
public void onPrepared(MediaPlayer player) {
player.start();
mPlayer.setLooping(true);
mPlayer.setVolume(25, 25);
}
}
最后，我想在没有停止/开始音乐的所有活动中播放背景音乐。 我该怎么办？
答案 0 :(得分：8)
您可以将音乐播放器置于服务中。这将使其独立于活动，您仍然可以通过意图控制回放。
以下是一些代码示例：https://stackoverflow.com/a/8209975/2804473 下面的代码由Synxmax在StackOverflow上编写，并在上面的链接中介绍：
public class BackgroundSoundService extends Service {
private static final String TAG = null;
MediaPlayer player;
public IBinder onBind(Intent arg0) {
return null;
}
@Override
public void onCreate() {
super.onCreate();
player = MediaPlayer.create(this, R.raw.idil);
player.setLooping(true); // Set looping
player.setVolume(100,100);
}
public int onStartCommand(Intent intent, int flags, int startId) {
player.start();
return 1;
}
public void onStart(Intent intent, int startId) {
// TO DO
}
public IBinder onUnBind(Intent arg0) {
// TO DO Auto-generated method
return null;
}
public void onStop() {
}
public void onPause() {
}
@Override
public void onDestroy() {
player.stop();
player.release();
}
@Override
public void onLowMemory() {
}
}
答案 1 :(得分：0)
public class serv extends Service{
MediaPlayer mp;
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
public void onCreate()
{
mp = MediaPlayer.create(this, R.raw.b);
mp.setLooping(false);
}
public void onDestroy()
{
mp.stop();
}
public void onStart(Intent intent,int startid){
Log.d(tag, "On start");
mp.start();
}
}
答案 2 :(得分：0)
@Override
public void onCreate (){
super.onCreate();
Player = MediaPlayer.create(this, R.raw.jingle);
mPlayer.setOnErrorListener(this);
if(mPlayer!= null)
{
mPlayer.setLooping(true);
mPlayer.setVolume(100,100);
}
mPlayer.setOnErrorListener(new OnErrorListener() {
public boolean onError(MediaPlayer mp, int what, int
extra){
onError(mPlayer, what, extra);
return true;
}
});
}
答案 3 :(得分：0)
最正确的答案是正确的，但是您必须将服务添加到清单文件中。
<service android:enabled="true" android:name="BackgroundSoundService" />
答案 4 :(得分：0)
上述西蒙的答案是正确的。我遇到类似的问题，即我的片段带有音乐播放器，并且需要单击按钮返回到该UI。您的情况类似，但是您想控制回放而不是返回UI。这是我为应用程序所做的。这需要播放音频列表，包括随机播放和重复播放功能。这样也可以在通知栏中显示媒体控件。
MusicPlayerService：
public class MediaPlayerService extends Service implements MediaPlayer.OnCompletionListener,
MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener, MediaPlayer.OnSeekCompleteListener,
MediaPlayer.OnInfoListener, MediaPlayer.OnBufferingUpdateListener,
AudioManager.OnAudioFocusChangeListener {
public static final String ACTION_PLAY = "pkg_name.ACTION_PLAY";
public static final String ACTION_PAUSE = "pkg_name.ACTION_PAUSE";
public static final String ACTION_PREVIOUS = "pkg_name.ACTION_PREVIOUS";
public static final String ACTION_NEXT = "pkg_name.ACTION_NEXT";
public static final String ACTION_STOP = "pkg_name.ACTION_STOP";
private MediaPlayer mediaPlayer;
//MediaSession
private MediaSessionManager mediaSessionManager;
private MediaSessionCompat mediaSession;
private MediaControllerCompat.TransportControls transportControls;
//AudioPlayer notification ID
private static final int NOTIFICATION_ID = 101;
//Used to pause/resume MediaPlayer
private int resumePosition;
// Binder given to clients
private final IBinder iBinder = new LocalBinder();
//List of available Audio files
private ArrayList audioList;
private int audioIndex = -1;
//Handle incoming phone calls
private boolean ongoingCall = false;
private PhoneStateListener phoneStateListener;
private TelephonyManager telephonyManager;
private Bitmap albumArtBitmap;
private boolean shuffle = false;
private boolean repeat = false;
private Random rand;
/**
* Service lifecycle methods
*/
@Override
public IBinder onBind(Intent intent) {
return iBinder;
}
@Override
public void onCreate() {
super.onCreate();
// Perform one-time setup procedures
// Manage incoming phone calls during playback.
// Pause MediaPlayer on incoming call,
// Resume on hangup.
callStateListener();
//ACTION_AUDIO_BECOMING_NOISY -- change in audio outputs -- BroadcastReceiver
registerBecomingNoisyReceiver();
//Listen for new Audio to play -- BroadcastReceiver
register_playNewAudio();
rand = new Random();
StorageUtil storage = new StorageUtil(getApplicationContext());
shuffle = storage.loadShuffleRepeat("Shuffle");
repeat = storage.loadShuffleRepeat("Repeat");
}
//The system calls this method when an activity, requests the service be started
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
try {
//Load data from SharedPreferences
StorageUtil storage = new StorageUtil(getApplicationContext());
audioList = storage.loadAudio();
audioIndex = storage.loadAudioIndex();
if (audioIndex != -1 && audioIndex ready to receive media commands
mediaSession.setActive(true);
//indicate that the MediaSession handles transport control commands
// through its MediaSessionCompat.Callback.
mediaSession.setFlags(MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
//Set mediaSession's MetaData
updateMetaData();
// Attach Callback to receive MediaSession updates
mediaSession.setCallback(new MediaSessionCompat.Callback() {
// Implement callbacks
@Override
public void onPlay() {
super.onPlay();
resumeMedia();
}
@Override
public void onPause() {
super.onPause();
pauseMedia();
}
});
}
private void updateMetaData() {
fetchBitmapOfAlbum();
// Update the current metadata
mediaSession.setMetadata(new MediaMetadataCompat.Builder()
.putBitmap(MediaMetadataCompat.METADATA_KEY_ALBUM_ART, albumArtBitmap)
.putString(MediaMetadataCompat.METADATA_KEY_ARTIST, "")
.putString(MediaMetadataCompat.METADATA_KEY_ALBUM, activeAudio.getAlbumName())
.putString(MediaMetadataCompat.METADATA_KEY_TITLE, activeAudio.getTrackName())
.build());
}
private Target target = new Target() {
@Override
public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
albumArtBitmap = bitmap;
}
@Override
public void onBitmapFailed(Exception e, Drawable errorDrawable) {
}
@Override
public void onPrepareLoad(Drawable placeHolderDrawable) {
}
};
private void fetchBitmapOfAlbum() {
Picasso.get().load(activeAudio.getAlbumArt())
.placeholder(R.drawable.rotate_animation)
.error(R.drawable.ic_blank)
.into(target);
}
private void buildNotification(PlaybackStatus playbackStatus) {
int notificationAction = android.R.drawable.ic_media_pause;//needs to be initialized
PendingIntent play_pauseAction = null;
//Build a new notification according to the current state of the MediaPlayer
if (playbackStatus == PlaybackStatus.PLAYING) {
notificationAction = android.R.drawable.ic_media_pause;
//create the pause action
play_pauseAction = playbackAction(1);
} else if (playbackStatus == PlaybackStatus.PAUSED) {
notificationAction = android.R.drawable.ic_media_play;
//create the play action
play_pauseAction = playbackAction(0);
}
fetchBitmapOfAlbum(); //replace with your own image
String channelId = "";
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
channelId = "APP_MUSIC";
}
// Create a new Notification
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, channelId)
// Hide the timestamp
.setShowWhen(false)
// Set the Notification style
.setStyle(new androidx.media.app.NotificationCompat.MediaStyle()
// Attach our MediaSession token
.setMediaSession(mediaSession.getSessionToken())
// Show our playback controls in the compat view
.setShowActionsInCompactView(0, 1, 2))
// Set the Notification color
.setColor(ContextCompat.getColor(this.getApplicationContext(), R.color.colorAccent))
// Set the large and small icons
.setLargeIcon(albumArtBitmap)
.setSmallIcon(R.drawable.ic_stat_notifications)
// Set Notification content information
.setContentText(activeAudio.getTrackName())
.setTicker(activeAudio.getAlbumName() + "-" + activeAudio.getTrackName())
.setOngoing(true)
.setContentTitle(activeAudio.getAlbumName())
.setContentInfo(activeAudio.getTrackName())
// Add playback actions
.addAction(notificationAction, "pause", play_pauseAction)
((NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE)).notify(NOTIFICATION_ID, notificationBuilder.build());
}
private PendingIntent playbackAction(int actionNumber) {
Intent playbackAction = new Intent(this, MediaPlayerService.class);
switch (actionNumber) {
case 0:
// Play
playbackAction.setAction(ACTION_PLAY);
return PendingIntent.getService(this, actionNumber, playbackAction, 0);
case 1:
// Pause
playbackAction.setAction(ACTION_PAUSE);
return PendingIntent.getService(this, actionNumber, playbackAction, 0);
default:
break;
}
return null;
}
private void removeNotification() {
NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.cancel(NOTIFICATION_ID);
}
private void handleIncomingActions(Intent playbackAction) {
if (playbackAction == null || playbackAction.getAction() == null) return;
String actionString = playbackAction.getAction();
if (actionString.equalsIgnoreCase(ACTION_PLAY)) {
transportControls.play();
} else if (actionString.equalsIgnoreCase(ACTION_PAUSE)) {
transportControls.pause();
}
}
/**
* Play new Audio
*/
private BroadcastReceiver playNewAudio = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
//Get the new media index form SharedPreferences
audioIndex = new StorageUtil(getApplicationContext()).loadAudioIndex();
if (audioIndex != -1 && audioIndex
- Add the service to your manifest
<service android:name=".service.MediaPlayerService" />
- Bind the service in MainActivity and declare methods to call the service
<service android:name=".service.MediaPlayerService" />