Androidバックグラウンドで音楽を再生する
以下のような私の活動コードがあります：
public class Player extends Activity implements OnCompletionListener,
OnPreparedListener, OnErrorListener, OnBufferingUpdateListener, MusicFocusable {
private Boolean playState = false;
private String station = "http://38.101.19.5:9157";
public static final float DUCK_VOLUME = 0.1f;
private String artistName = null;
private String trackName = null;
private TextView artist;
private TextView track;
private TextView status;
private Button play;
enum AudioFocus {
NoFocusNoDuck, // we don't have audio focus, and can't duck
NoFocusCanDuck, // we don't have focus, but can play at a low volume
// ("ducking")
Focused // we have full audio focus
}
private AudioFocus mAudioFocus = AudioFocus.NoFocusNoDuck;
private MediaPlayer mPlayer = null;
private AndroidShoutcastLib shoutcast;
private AudioManager mAudioManager;
AudioFocusHelper mAudioFocusHelper = null;
Handler handler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_player);
mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
// create the Audio Focus Helper, if the Audio Focus feature is
// available (SDK 8 or above)
if (Android.os.Build.VERSION.SDK_INT >= 8) {
mAudioFocusHelper = new AudioFocusHelper(getApplicationContext(),
this);
}
else {
mAudioFocus = AudioFocus.Focused; // no focus feature, so we always "have" audio focus
}
status = (TextView) findViewById(R.id.status);
artist = (TextView) findViewById(R.id.artist);
artist.setSelected(true);
track = (TextView) findViewById(R.id.track);
track.setSelected(true);
play = (Button) findViewById(R.id.play);
play.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View btn) {
if (!playState) {
play.setText("Pause");
handler.postDelayed(handlePlayRequest, 300);
}
else {
play.setText("Play");
status.setText("Press Play");
handler.postDelayed(handlePlayRequest, 300);
}
}
});
shoutcast = new AndroidShoutcastLib();
try {
shoutcast.setShoutcastUrl(station);
} catch (InvalidStreamURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
shoutcast.setOnMetadataChangedListener(new MetadataListener(){
@Override
public void OnMetadataChanged(Metadata item) {
artistName = item.artist;
trackName = item.track;
updateMeta();
}
});
setVolumeControlStream(AudioManager.STREAM_MUSIC);
}
public void onDestroy() {
super.onDestroy();
shoutcast = null;
handler.removeCallbacks(handlePlayRequest);
}
public void updateMeta() {
handler.post(new Runnable() {
@Override
public void run() {
// This gets executed on the UI thread so it can safely modify Views
artist.setText(artistName);
track.setText(trackName);
}
});
}
private final Runnable handlePlayRequest = new Runnable() {
public void run() {
if (playState) {
Log.d("Player", "Stop Called");
giveUpAudioFocus();
mPlayer.stop();
mPlayer.reset();
mPlayer.release();
shoutcast.stopStream();
mPlayer = null;
playState = false;
}
else {
Log.d("Player", "Play Called");
createMediaPlayer();
getAudioFocus();
try {
mPlayer.setDataSource(shoutcast.startStream());
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SecurityException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidStreamURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mPlayer.prepareAsync();
}
}
};
private void createMediaPlayer() {
mPlayer = new MediaPlayer();
// Make sure the media player will acquire a wake-lock while
// playing. If we don't do
// that, the CPU might go to sleep while the song is playing,
// causing playback to stop.
//
// Remember that to use this, we have to declare the
// Android.permission.WAKE_LOCK
// permission in AndroidManifest.xml.
mPlayer.setWakeMode(getApplicationContext(),
PowerManager.PARTIAL_WAKE_LOCK);
// we want the media player to notify us when it's ready preparing,
// and when it's done
// playing:
mPlayer.setOnPreparedListener(this);
mPlayer.setOnCompletionListener(this);
mPlayer.setOnErrorListener(this);
}
private void startPlayer() {
mPlayer.setVolume(1.0f, 1.0f);
if (!mPlayer.isPlaying()) {
Log.d("Player", "Starting Playback");
mPlayer.start();
playState = true;
status.setText("Streaming");
}
}
private void getAudioFocus() {
if (mAudioFocus != AudioFocus.Focused && mAudioFocusHelper != null
&& mAudioFocusHelper.requestFocus())
mAudioFocus = AudioFocus.Focused;
}
private void giveUpAudioFocus() {
if (mAudioFocus == AudioFocus.Focused && mAudioFocusHelper != null
&& mAudioFocusHelper.abandonFocus())
mAudioFocus = AudioFocus.NoFocusNoDuck;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_player, menu);
return true;
}
@Override
public void onBufferingUpdate(MediaPlayer arg0, int arg1) {
// TODO Auto-generated method stub
}
@Override
public boolean onError(MediaPlayer mp, int what, int extra) {
playState = false;
handler.post(handlePlayRequest);
return false;
}
@Override
public void onPrepared(MediaPlayer arg0) {
startPlayer();
}
@Override
public void onCompletion(MediaPlayer arg0) {
// TODO Auto-generated method stub
}
@Override
public void onGainedAudioFocus() {
// TODO Auto-generated method stub
}
@Override
public void onLostAudioFocus(boolean canDuck) {
// TODO Auto-generated method stub
}
}
私の要件は、このアクティビティをサービスクラスに変換することです。私は試しましたが、取得していません。Androidとプログラミングが初めてなので、
誰か助けてもらえますか？
アプリで音楽を再生する必要があるだけの場合は、アプリ/ useAsyncTaskクラスから起動したスレッドで音楽を再生してください。
このコードを使用します。このクラスを追加します（アクティビティクラスで囲まれています）。
public class BackgroundSound extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
MediaPlayer player = MediaPlayer.create(YourActivity.this, R.raw.test_cbr);
player.setLooping(true); // Set looping
player.setVolume(100,100);
player.start();
return null;
}
}
一方、サービスを利用したい場合は このページ を参照してください。
実行するいくつかの手順.....
1.まずサービス例を確認します。
2.このアクティビティからサービスを開始します。つまり、このアプリを開いたときにアクティビティをナビゲートして、アクティビティにサービスを提供します--->サービス。
3.インサービスのonstart（）オーバーライド。
4. onstart（）でmusicplayer関数を作成し、必要な曲を作成します。
5.そして、このmp.play（）;のように開始します。
6.バックグラウンドで実行されます