如何在Android应用程序的后台播放音乐？
如何在Android应用程序的后台播放音乐？
提问于 2018-09-30 03:02:45
我想在我的应用程序中播放音乐而不管应用程序中发生了什么。我正在尝试实现它Service。这是MyService.class
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
public class MyService extends Service implements MediaPlayer.OnPreparedListener {
MediaPlayer mMediaPlayer = null;
private static final String ACTION_PLAY = "com.example.action.PLAY";
public MyService() {
}
@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
public int onStartCommand(Intent intent, int flags, int startId) {
if (intent.getAction().equals(ACTION_PLAY)) {
mMediaPlayer = MediaPlayer.create(this, R.raw.theme_song);
mMediaPlayer.setOnPreparedListener(this);
mMediaPlayer.prepareAsync(); // prepare async to not block main thread
return 1;
} else {
return 0;
}
}
public void onPrepared(MediaPlayer player) {
player.start();
}
}
你能帮我解决一下我Service在MyActivity中的使用方法，以及MyService.class中需要定义的其他方法才能得到正确的结果。
回答 2
Stack Overflow用户
发布于 2018-09-30 11:07:29
public class BackGroundMusic extends Service {
MediaPlayer mediaPlayer;
AudioManager audioManager;
int volume;
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
mediaPlayer = MediaPlayer.create(this, R.raw.tune);
mediaPlayer.start();
return super.onStartCommand(intent, flags, startId);
}
@Override
public boolean stopService(Intent name) {
return super.stopService(name);
}
@Override
public void onDestroy() {
super.onDestroy();
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = null;
}
}
如果你需要播放音乐
startService(new Intent(MainActivity.this, BackGroundMusic.class))
如果你想停止音乐
stopService(new Intent(MainActivity.this, BackGroundMusic.class))..
Stack Overflow用户
发布于 2018-09-30 12:51:26
1.制作后台服务
package service;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.support.annotation.Nullable;
import java.io.IOException;
public class BackgroundSoundService extends Service {
MediaPlayer mPlayer = null;
private final static int MAX_VOLUME = 100;
Context context;
AudioManager.OnAudioFocusChangeListener afChangeListener;
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
int musicflag = (int) intent.getExtras().get("songindex");
if (musicflag == 1) {
playMusic(R.raw.s1_pondambience);
} else {
playMusic(R.raw.s2_integrative_music);
}
return Service.START_REDELIVER_INTENT;
}
@Override
public void onDestroy() {
super.onDestroy();
if (mPlayer != null) {
try {
mPlayer.stop();
mPlayer.release();
} finally {
mPlayer = null;
}
}
}
public void onTaskRemoved(Intent rootIntent) {
stopSelf();
}
/*
* playmusic custom method for manage two different background sounds for application
* */
public void playMusic(int musicFile) {
if (mPlayer != null) {
if (mPlayer.isPlaying()) {
try {
mPlayer.stop();
mPlayer.release();
mPlayer = MediaPlayer.create(this, musicFile);
AudioManager am = (AudioManager) getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
int result = am.requestAudioFocus(afChangeListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
// Start playback.
mPlayer.setLooping(true);
final float volume = (float) (1 - (Math.log(MAX_VOLUME - 85) / Math.log(MAX_VOLUME)));
mPlayer.setVolume(volume, volume);
mPlayer.start();
}
} catch (Exception e) {
e.printStackTrace();
}
} else {
try {
mPlayer = MediaPlayer.create(this, musicFile);
AudioManager am = (AudioManager) getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
int result = am.requestAudioFocus(afChangeListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
// Start playback.
mPlayer.setLooping(true);
final float volume = (float) (1 - (Math.log(MAX_VOLUME - 85) / Math.log(MAX_VOLUME)));
mPlayer.setVolume(volume, volume);
mPlayer.prepare();
mPlayer.start();
}
} catch (IOException e) {
e.printStackTrace();
}
}
} else {
try {
mPlayer = MediaPlayer.create(this, musicFile);
AudioManager am = (AudioManager) getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
int result = am.requestAudioFocus(afChangeListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
// Start playback.
mPlayer.setLooping(true);
final float volume = (float) (1 - (Math.log(MAX_VOLUME - 85) / Math.log(MAX_VOLUME)));
mPlayer.setVolume(volume, volume);
mPlayer.start();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
/*
* MediaPlayer methods
* */
public void pauseMusic() {
if (mPlayer.isPlaying()) {
mPlayer.pause();
length = mPlayer.getCurrentPosition();
}
}
public void resumeMusic() {
if (mPlayer.isPlaying() == false) {
mPlayer.seekTo(length);
mPlayer.start();
}
}
public void stopMusic() {
mPlayer.stop();
mPlayer.release();
mPlayer = null;
}
public boolean onError(MediaPlayer mp, int what, int extra) {
if (mPlayer != null) {
try {
mPlayer.stop();
mPlayer.release();
} finally {
mPlayer = null;
}
}
return false;
}
}
并随时启动和停止服务。
2.使用以下方法启动服务
private void startBackMusic() {
Intent musicintent = new Intent(MenuActivity.this, BackgroundSoundService.class);
musicintent.putExtra(EXTRA_SONGINDEX, 1);
startService(musicintent);
}
3.停止服务使用以下方法
private void stopBackMusic() {
Intent musicintent = new Intent(MenuActivity.this, BackgroundSoundService.class);
stopService(musicintent);
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/-100002823
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