Android 在后台播放音乐 [英] Android playing Music in Background
本文介绍了Android 在后台播放音乐的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的活动代码如下:
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
}
}
我的要求是将此活动转换为服务类，我尝试过但没有得到，因为我是 Android 新手以及编程新手，
My Requirement is to Convert this Activity to Service Class,I have tried but not getting,Because I'm new to Android as well as new to Programing,
有人可以帮忙吗?
推荐答案
如果您只需要在您的应用中播放音乐，请在从您的应用启动的线程中播放/使用 AsyncTask 类来执行给你.
If you just need to play music in your app, play it in a thread launched from your app/use AsyncTask class to do it for you.
使用此代码.添加这个类(包含在您的活动类中).
Use this code. Add this class (Enclosed in your activity class).
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;
}
}
另一方面，如果你想使用一个服务，你可以查看本页.
On the other hand, if you want to use a service you can look at this page.
这篇关于Android 在后台播放音乐的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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