Java 屏幕关闭时继续播放音乐

我想继续播放音乐，即使屏幕关闭（即使用户锁定了手机），当用户按下home（主页）按钮时暂停，再次返回应用程序应允许他从暂停的位置继续播放音乐…类似于用户通过文件浏览器播放音乐

这是我的密码：

public class prathmeshvara extends AppCompatActivity implements Runnable,  View.OnClickListener, SeekBar.OnSeekBarChangeListener{
TextView tv25;
Button b47, b48, but32;
int count = 0;
MediaPlayer play3;
SeekBar seek_bar3;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_prathmeshvara);
    ActionBar actionBar=getSupportActionBar();
    actionBar.setDisplayShowHomeEnabled(true);
    actionBar.setIcon(R.mipmap.icon);
    tv25 = (TextView) findViewById(R.id.textView25);
    tv25.setText(Html.fromHtml(getString(R.string.twentyone)));
    b47 = (Button) findViewById(R.id.b47);
    b48 = (Button) findViewById(R.id.b48);
    seek_bar3 = (SeekBar) findViewById(R.id.seekBar3);
    seek_bar3.setOnSeekBarChangeListener(this);
    seek_bar3.setEnabled(false);
    but32 = (Button) findViewById(R.id.button32);
    but32.setOnClickListener(this);
}

public void run() {
    int currentPosition = play3.getCurrentPosition();
    final int total = play3.getDuration();
    while (play3 != null && currentPosition < total) {
        try {
            Thread.sleep(1000);
            currentPosition = play3.getCurrentPosition();
        } catch (InterruptedException e) {
            return;
        } catch (Exception e) {
            return;
        }
        seek_bar3.setProgress(currentPosition);
    }
}

public void onClick(View v) {
    if (v.equals(but32)) {
        if (play3 == null) {
            play3 = MediaPlayer.create(getApplicationContext(), R.raw.prathameshwara);
            seek_bar3.setEnabled(true);
        }
        if (play3.isPlaying()) {
            play3.pause();
            but32.setBackgroundResource(R.drawable.play);
        } else {
            play3.start();
            but32.setBackgroundResource(R.drawable.pause);
            seek_bar3.setMax(play3.getDuration());
            new Thread(this).start();
        }
    }
    play3.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            play3.seekTo(0);
            but32.setBackgroundResource(R.drawable.play);
        }
    });
}

@Override
protected void onPause()
{
    super.onPause();
    if (play3!= null)
    {
        play3.pause();
    }
}

@Override
protected void onResume()
{
    super.onResume();
    if ((play3 != null) && (!play3.isPlaying())) {
        but32.setBackgroundResource(R.drawable.play);
        but32.setOnClickListener(this);
    }
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
    try {
        if (play3.isPlaying() || play3 != null) {
            if (fromUser)
                play3.seekTo(progress);
        } else if (play3 == null) {
            Toast.makeText(getApplicationContext(), "First Play", Toast.LENGTH_SHORT).show();
            seek_bar3.setProgress(0);
        }
    } catch (Exception e) {
        Log.e("seek bar", "" + e);
        seek_bar3.setEnabled(false);
    }
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {

}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {

}
}

公共类prathmeshvara扩展AppCompatActivity实现Runnable、View.OnClickListener、SeekBar.OnSeekbarChangListener{
文本视图tv25；
按钮b47、b48、but32；
整数计数=0；
MediaPlayer play3；
SeekBar seek_bar3；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_Pratheshvara）；
ActionBar ActionBar=getSupportActionBar（）；
actionBar.setDisplayShowHomeEnabled（真）；
actionBar.setIcon（R.mipmap.icon）；
tv25=（TextView）findViewById（R.id.textView25）；
setText（Html.fromHtml（getString（R.string.twentytone））；
b47=（按钮）findViewById（R.id.b47）；
b48=（按钮）findViewById（R.id.b48）；
seek_bar3=（SeekBar）findViewById（R.id.seekBar3）；
seek_bar3.setonseekbarchaneglistener（这个）；
seek_bar3.setEnabled（false）；
but32=（按钮）findViewById（R.id.button32）；
但是32.setOnClickListener（这个）；
}
公开募捐{
int currentPosition=play3.getCurrentPosition（）；
final int total=play3.getDuration（）；
while（play3！=null&¤tPosition

基本上，为了达到你的目标，你不应该做

play3。在
onPause（）中暂停

@Override
protected void onPause()
{
    super.onPause();
    if (play3!= null)
    {
        play3.pause();
    }
}

现在，当你的应用程序进入onPause状态时，你的播放会暂停。
顺便说一句，别忘了花点时间实施AudioFocus处理。
我从以下来源了解了AudioFocus及其处理：






此外，在makeweight中，这里您有一些关于清理媒体资源的信息，以使您的应用程序不占用大量内存，并为其他应用程序发布媒体编解码器，以防它们也想使用它：


在您的玩家活动中，在
onCreate
之前：

import android.media.AudioManager;


在
onClick
方法中：

int result = mAudioManager.requestAudioFocus(mOnAudioFocusChangeListener,
                    AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);

            if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED){
                // we have audio focus now

                // Create and setup the {@link MediaPlayer} for the audio resource associated with the current word
                mMediaPlayer = MediaPlayer.create(YourActivity.this, word.getAudioResourceId());

                // Start the audio file
                mMediaPlayer.start();

                // Setup a listener on the media player, so that we can stop and release the
                // media player once the sound has finished playing.
                mMediaPlayer.setOnCompletionListener(mCompletionListener);
            }

此外，我建议您将此项添加到播放器活动中（但不在
onCreate
中），以便正确释放媒体资源，并在按下停止按钮时使用此项，在其他情况下应停止播放：

/**
 * Clean up the media player by releasing its resources.
 */
private void releaseMediaPlayer() {
    // If the media player is not null, then it may be currently playing a sound.
    if (mMediaPlayer != null) {
        // Regardless of the current state of the media player, release its resources
        // because we no longer need it.
        mMediaPlayer.release();

        // Set the media player back to null. For our code, we've decided that
        // setting the media player to null is an easy way to tell that the media player
        // is not configured to play an audio file at the moment.
        mMediaPlayer = null;

        // Regardless of whether or not we were granted audio focus, abandon it. This also
        // unregisters the AudioFocusChangeListener so we don't get anymore callbacks.
        mAudioManager.abandonAudioFocus(mOnAudioFocusChangeListener);
    }
}

你能帮我解决一下AudioFocusant吗？只是对我现有的代码做一些修改，然后解决问题……我无法得到，因为我最近开始编码。。。。
/**
 * Clean up the media player by releasing its resources.
 */
private void releaseMediaPlayer() {
    // If the media player is not null, then it may be currently playing a sound.
    if (mMediaPlayer != null) {
        // Regardless of the current state of the media player, release its resources
        // because we no longer need it.
        mMediaPlayer.release();

        // Set the media player back to null. For our code, we've decided that
        // setting the media player to null is an easy way to tell that the media player
        // is not configured to play an audio file at the moment.
        mMediaPlayer = null;

        // Regardless of whether or not we were granted audio focus, abandon it. This also
        // unregisters the AudioFocusChangeListener so we don't get anymore callbacks.
        mAudioManager.abandonAudioFocus(mOnAudioFocusChangeListener);
    }
}