在我的应用中，我正在使用媒体播放器播放单个音频文件（12 mb）。该应用程序包含三个活动ManiActivity，MWlyrics和About。 音频正在MainActivity中播放，问题是当我在这些活动之间切换时。音频停止播放。
public class MainActivity extends AppCompatActivity {
private MediaPlayer mp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mp = MediaPlayer.create(this, R.raw.abc);
getSupportActionBar().setElevation(0);
ImageView imageView = (ImageView)findViewById(R.id.main_img_lm);
Glide.with(this).load(R.drawable.lm)
.thumbnail(0.5f)
.into(imageView);
}
//play song method
public void playSong (View v){
mp.start();
}
//pause song method
public void pauseSong (View v){
mp.pause();
}
//stop song method
public void stopSong (View v){
mp.stop();
mp = MediaPlayer.create(this, R.raw.abc);
}
// main menu
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menur, menu);
menu.add(0, 1, 1, menuIconWithText(getResources().getDrawable(R.drawable.ic_rate), getResources().getString(R.string.rate_us)));
menu.add(0, 2, 2, menuIconWithText(getResources().getDrawable(R.drawable.ic_apps), getResources().getString(R.string.more_apps)));
menu.add(0, 3, 3, menuIconWithText(getResources().getDrawable(R.drawable.ic_share), getResources().getString(R.string.share_app)));
menu.add(0, 4, 4, menuIconWithText(getResources().getDrawable(R.drawable.ic_info), getResources().getString(R.string.about)));
menu.add(0, 5, 5, menuIconWithText(getResources().getDrawable(R.drawable.ic_exit), getResources().getString(R.string.exit)));
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case 1:
Toast.makeText(MainActivity.this, "redirecting to rate us and review page page", Toast.LENGTH_SHORT).show();
return true;
case 2:
Toast.makeText(MainActivity.this, "thank you for using", Toast.LENGTH_SHORT).show();
return true;
case 3:
Toast.makeText(MainActivity.this, "sharing app..", Toast.LENGTH_SHORT).show();
return true;
case 4:
Toast.makeText(MainActivity.this, "about this app", Toast.LENGTH_SHORT).show();
Intent j = new Intent(this,About.class);
startActivity(j);
return true;
case 5:
finish();
mp.release();
return true;
case R.id.mdwtid:
Intent i = new Intent(this,MWLyrics.class);
startActivity(i);
return true;
}
return super.onOptionsItemSelected(item);
}
private CharSequence menuIconWithText(Drawable r, String title) {
r.setBounds(0, 0, r.getIntrinsicWidth(), r.getIntrinsicHeight());
SpannableString sb = new SpannableString(" " + title);
ImageSpan imageSpan = new ImageSpan(r, ImageSpan.ALIGN_BOTTOM);
sb.setSpan(imageSpan, 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
return sb;
}
}
应用程序详细信息..
MainActiviy-显示专辑图像和[播放，暂停和停止]图像。
Mwlyrics-显示歌曲歌词。
关于-显示应用信息。
如何解决此问题。
如何在其他活动之间切换时继续播放音频而不会受到任何干扰。
如何在应用程序中有效使用此音频文件..考虑到内存。
当在我的移动设备上测试应用程序（moto one power，android pie）时，我注意到频率（有时运行40％）和最大使用量为170 mb。这到底是什么意思。我是android开发的新手，我需要一些建议。
答案 0 :(得分：1)
您需要为此使用服务。您可以检查以下代码
class BackgroundAudioService extends Service implements OnCompletionListener {
MediaPlayer mediaPlayer;
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate() {
mediaPlayer = MediaPlayer.create(this, R.raw.s);// raw/s.mp3
mediaPlayer.setOnCompletionListener(this);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (!mediaPlayer.isPlaying()) {
mediaPlayer.start();
}
return START_STICKY;
}
public void onDestroy() {
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
}
mediaPlayer.release();
}
public void onCompletion(MediaPlayer _mediaPlayer) {
stopSelf();
}
}
您可以像这样启动服务
public class Test extends Activity implements OnClickListener {
Button startPlaybackButton, stopPlaybackButton;
Intent playbackServiceIntent;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
startPlaybackButton = (Button) this.findViewById(R.id.StartPlaybackButton);
stopPlaybackButton = (Button) this.findViewById(R.id.StopPlaybackButton);
startPlaybackButton.setOnClickListener(this);
stopPlaybackButton.setOnClickListener(this);
playbackServiceIntent = new Intent(this, BackgroundAudioService.class);
}
public void onClick(View v) {
if (v == startPlaybackButton) {
startService(playbackServiceIntent);
finish();
} else if (v == stopPlaybackButton) {
stopService(playbackServiceIntent);
finish();
}
}
}
答案 1 :(得分：0)
请检查下面的实用程序类代码以从您的代码中的任何位置播放音频，并提供所有选项开始、停止、释放声音调整等...
class AudioPlayer {
private var mPlayer: MediaPlayer? = null
companion object{
var mContext:Context?= null
var audioplayer : AudioPlayer?= null
fun getInstance(context: Context): AudioPlayer {
this.mContext = context;
if(audioplayer == null){
audioplayer = AudioPlayer()
}
return audioplayer!!
}
}
fun getPlayer():MediaPlayer?{
return mPlayer
}
fun adjustSound(){
try {
val am: AudioManager =
mContext!!.getSystemService(Context.AUDIO_SERVICE) as AudioManager
initVolume = am.getStreamVolume(AudioManager.STREAM_MUSIC);
maxVolume = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
// am.setStreamVolume(
// AudioManager.STREAM_MUSIC,
// am.getStreamMaxVolume(AudioManager.STREAM_MUSIC),
// 0
// )
//
// am.adjustVolume(AudioManager.ADJUST_SAME, AudioManager.FLAG_PLAY_SOUND)
}catch (e:Exception){
e.printStackTrace()
}
}
fun initMediaPlayer(uriAudio: Uri) {
try {
// if (mPlayer == null) {
// releaseMediaPlayer()
adjustSound()
// mPlayer = MediaPlayer()
mPlayer = MediaPlayer.create(mContext, myUri(uriAudio))
if (Build.VERSION.SDK_INT >= 21) {
val audioAttributes: AudioAttributes =
AudioAttributes.Builder()
.setUsage(AudioAttributes.USAGE_MEDIA)
.setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
.build()
mPlayer!!.setAudioAttributes(audioAttributes)
} else {
mPlayer!!.setAudioStreamType(AudioManager.STREAM_MUSIC)
}
// }
} catch (e: Exception) {
e.printStackTrace()
}
}
var initVolume : Int = 0
var maxVolume : Int = 0
var volumes:Float = -1f
fun setVolume(progress:Float){
try {
volumes =
(1 - Math.log((100 - progress).toDouble()) / Math.log(100.0)).toFloat()
if(mPlayer!=null) {
mPlayer!!.setVolume(volumes, volumes)
}
}catch (e:java.lang.Exception){
e.printStackTrace()
}
}
fun getVolume():Float{
if(volumes < 0.0){
volumes = 1.0f
}
return volumes
}
interface PlayerProgress{
fun onProgressUpdate(progress:Int)
fun onComplete(progress:Int)
}
var isprePared : Boolean = false
fun initMediaPlayer(uriAudio: Uri,isAdjusSound:Boolean,playerProgress: PlayerProgress) {
isprePared = false
try {
if(isAdjusSound){
adjustSound()
}
// mPlayer = MediaPlayer()
mPlayer = MediaPlayer.create(mContext, myUri(uriAudio))
// try {
// mPlayer!!.prepare()
// } catch (e: IOException) {
// e.printStackTrace()
// }
// if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
// val speed = 0.25f
// mPlayer!!.setPlaybackParams(mPlayer!!.getPlaybackParams().setSpeed(speed))
// }
// if(isAdjusSound) {
// val volume = (initVolume / maxVolume).toFloat()
// mPlayer!!.setVolume(volume, volume)
// }
if (Build.VERSION.SDK_INT >= 21) {
val audioAttributes: AudioAttributes =
AudioAttributes.Builder()
// .setFlags(AudioAttributes.FLAG_AUDIBILITY_ENFORCED)
// .setLegacyStreamType(AudioManager.STREAM_MUSIC)
.setUsage(AudioAttributes.USAGE_MEDIA)
.setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
.build()
mPlayer!!.setAudioAttributes(audioAttributes)
} else {
mPlayer!!.setAudioStreamType(AudioManager.STREAM_MUSIC)
}
mPlayer!!.setOnBufferingUpdateListener(OnBufferingUpdateListener{ mediaPlayer: MediaPlayer, i: Int ->
if(playerProgress!=null) {
playerProgress.onProgressUpdate(i)
}
})
mPlayer!!.setOnCompletionListener {
if(playerProgress!=null) {
playerProgress.onComplete(0)
}
}
mPlayer!!.setOnBufferingUpdateListener(OnBufferingUpdateListener{ mediaPlayer: MediaPlayer, i: Int ->
if(playerProgress!=null) {
playerProgress.onProgressUpdate(i)
}
})
mPlayer!!.setOnPreparedListener() {
isprePared = true
}
} catch (e:IllegalStateException) {
e.printStackTrace();
}catch (e: Exception) {
e.printStackTrace()
}
}
fun myUri(originalUri: Uri): Uri? {
var returnedUri: Uri? = null
returnedUri = if (originalUri.scheme == null) {
Uri.fromFile(File(originalUri.getPath()))
// or you can just do -->
// returnedUri = Uri.parse("file://"+camUri.getPath());
} else {
originalUri
}
return returnedUri
}
fun playMediaPlayer() {
try {
if (mPlayer != null && !mPlayer!!.isPlaying/* && isprePared*/) {
mPlayer!!.start()
}
}catch (e:IllegalStateException) {
e.printStackTrace();
}catch (e:java.lang.Exception){
e.printStackTrace()
}
}
fun seektoMediaPlayer(msec:Int) {
try {
if (mPlayer != null/* && isprePared*/) {
mPlayer!!.seekTo(msec)
}
}catch (e:java.lang.Exception){
e.printStackTrace()
}
}
fun pauseMediaPlayer() {
try {
if (mPlayer != null/* && isprePared*/) {
mPlayer!!.pause()
}
}catch (e:java.lang.Exception){
e.printStackTrace()
}
}
fun prepareMeidaPlayer(uriAudio: Uri) {
try {
if (mPlayer != null) {
mPlayer!!.setDataSource(mContext!!, uriAudio)
mPlayer!!.prepare()
}
} catch (e: IOException) {
e.printStackTrace()
}
}
fun stopMediaPlayer(completstop:Boolean) {
try {
if (mPlayer != null) {
if (completstop) {
mPlayer!!.stop()
} else {
mPlayer!!.pause()
mPlayer!!.seekTo(0)
}
}
}catch (e:Exception){
e.printStackTrace()
}
}
fun releaseMediaPlayer(reset: Boolean) {
try {
if (mPlayer != null) {
if(reset){
mPlayer!!.reset()
mPlayer!!.stop()
}
mPlayer!!.release()
mPlayer = null
}
} catch (e: Exception) {
e.printStackTrace()
}
}
}
你可以这样打电话
AudioPlayer.getInstance(this)
.initMediaPlayer(Uri.parse(url), false, object : AudioPlayer.PlayerProgress {
override fun onProgressUpdate(progress: Int) {
// musicDialog.dismiss()
}
override fun onComplete(progress: Int) {
musicDialog.dismiss()
}
})
AudioPlayer.getInstance(this).playMediaPlayer()