壁纸服务保持音乐在后台播放，尽管应用程序已关闭

Question

在我的应用程序中，我想为用户提供一个使用WallpaeprService将动画设置为动态壁纸的选项，如果应用程序打开，我的应用程序还包括一个收音机播放器(在后台播放(，以便您可以在播放音乐时在其他应用程序中导航。

我的问题 ：

如果动态壁纸正常工作并且用户尝试通过(滑动退出/最近任务(关闭应用程序，尽管应用程序已关闭，但音乐仍在播放。

我试图停止这样的音乐，但不起作用：

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
@SuppressLint({"CommitPrefEdits", "Assert"})
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startService(new Intent(this, KillNotificationService.class));
trackSelector = new DefaultTrackSelector();
loadControl = new DefaultLoadControl();
exoPlayer = ExoPlayerFactory.newSimpleInstance(new DefaultRenderersFactory(getApplicationContext()), trackSelector, loadControl);
MusicButton.setVisibility(View.INVISIBLE);
MusicButton.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (Build.VERSION.SDK_INT > 15) {
if (started && MusicButton.isChecked()) {
started = false;
exoPlayer.setPlayWhenReady(false);
MusicButton.setChecked(true);
releaseAudioFocusForMyApp(MainActivity.this);
} else {
boolean gotFocus = requestAudioFocusForMyApp(MainActivity.this);
if (gotFocus) {
started = true;
exoPlayer.setPlayWhenReady(true);
MusicButton.setChecked(false);
}
}
} else {
if (started && MusicButton.isChecked()) {
started = false;
mediaPlayer.pause();
MusicButton.setChecked(true);
releaseAudioFocusForMyApp(MainActivity.this);
} else {
boolean gotFocus = requestAudioFocusForMyApp(MainActivity.this);
if (gotFocus) {
started = true;
mediaPlayer.start();
MusicButton.setChecked(false);
}
}
}
}
});

private void playRadio(String url) {
Uri audioUri = Uri.parse(url);
DefaultHttpDataSourceFactory dataSourceFactory = new DefaultHttpDataSourceFactory("ExoPlayerDemo");
ExtractorsFactory extractor = new DefaultExtractorsFactory();
MediaSource audioSource = new ExtractorMediaSource.Factory(dataSourceFactory).setExtractorsFactory(extractor).createMediaSource(audioUri);
exoPlayer.prepare(audioSource);
prepared = true;
exoPlayer.setPlayWhenReady(true);
exoPlayer.addListener(new Player.EventListener() {
@Override
public void onTimelineChanged(Timeline timeline, @Nullable Object manifest, int reason) {
}
@Override
public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
}
@Override
public void onLoadingChanged(boolean isLoading) {
}
@Override
public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
if (isPreparing && playbackState == ExoPlayer.STATE_READY) {
MusicButton.setVisibility(View.VISIBLE);
MusicButton.setChecked(true);
isPreparing = false;
isReady = true;
}
}
@Override
public void onRepeatModeChanged(int repeatMode) {
}
@Override
public void onShuffleModeEnabledChanged(boolean shuffleModeEnabled) {
}
@Override
public void onPlayerError(ExoPlaybackException error) {
}
@Override
public void onPositionDiscontinuity(int reason) {
}
@Override
public void onPlaybackParametersChanged(PlaybackParameters playbackParameters) {
}
@Override
public void onSeekProcessed() {
}
});
}

@Override
protected void onResume() {
super.onResume();
try {
MApplication.sBus.register(this);
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
protected void onStop() {
super.onStop();
}
@Override
protected void onDestroy() {
super.onDestroy();
try {
MApplication.sBus.unregister(this);
} catch (Exception e) {
e.printStackTrace();
}
MApplication.sBus.post(PlaybackEvent.PAUSE);
}
@Override
protected void onStart() {
super.onStart();
}
@Subscribe
public void handlePlaybackEvent(PlaybackEvent event) {
switch (event) {
case PAUSE:
if (Build.VERSION.SDK_INT > 15) {
if (exoPlayer.getPlayWhenReady()) {
exoPlayer.setPlayWhenReady(false);
MusicButton.setChecked(true);
}
} else {
if (mediaPlayer.isPlaying()) {
mediaPlayer.pause();
MusicButton.setChecked(true);
}
}
break;
case PLAY:
if (Build.VERSION.SDK_INT > 15) {
if (!exoPlayer.getPlayWhenReady()) {
exoPlayer.setPlayWhenReady(true);
MusicButton.setChecked(false);
}
} else {
if (!mediaPlayer.isPlaying()) {
mediaPlayer.start();
MusicButton.setChecked(false);
}
}
break;
}
}

@Override
public void onPause() {
super.onPause();
}
}
}

Answer 1

通过检查动态壁纸是否在背景中运行来解决的问题：

@Override
protected void onDestroy() {
super.onDestroy();
try {
WallpaperManager wpm = WallpaperManager.getInstance(this);
WallpaperInfo info = wpm.getWallpaperInfo();
if (info != null && info.getPackageName().equals(this.getPackageName())) {
/*stop music*/
} else {
Log.d(TAG, "We're not running");
}
} catch (Exception e) {
e.printStackTrace();
}
}