java - 如何自动将媒体播放器切换到下一首轨道？

Question

我正在尝试在歌曲结束时自动将播放器切换到下一首轨道，它会自动跟随必须重现的铃声。并且当前时间曲调应该在 texеview 中输出setOnCompletionListener - 不起作用，当前结束时不进入下一曲

//变量

        int[] soundsRawResIds = new int[]{R.raw.belarus, R.raw.russian, R.raw.japan,
            R.raw.litva, R.raw.england, R.raw.finlandia, R.raw.france};

    private final Handler handler = new Handler();

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.activity_main);
        initViews();
        currenttime=(TextView)findViewById(R.id.timeSound);
        buttonPlayStop = (Button) findViewById(R.id.ButtonPlayStop);

    }
    private void initViews() {
       mediaPlayer = MediaPlayer.create(this, soundsRawResIds[0]);
        seekBar = (SeekBar) findViewById(R.id.seekBar);
        seekBar.setMax(mediaPlayer.getDuration());
        seekBar.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                seekChange(v);

                return false;
            }
        });
    }


    private void seekChange(View v){
        if(mediaPlayer.isPlaying()){
            seekBar = (SeekBar)v;
            mediaPlayer.seekTo(seekBar.getProgress());


        }
    }
    public void playAndStop(View v){
        if (buttonPlayStop.getText() == getString(R.string.play_str)) {
            buttonPlayStop.setText(getString(R.string.pause_str));

                mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                    @Override
                    public void onCompletion(MediaPlayer mp) {
                        index++;
                        mp.reset();
                        if (index < soundsRawResIds.length) {
                            try {
                                AssetFileDescriptor afd = getResources().openRawResourceFd(soundsRawResIds[index]);
                                if (afd != null) {
                                    mp.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
                                    afd.close();
                                    mp.prepare();
                                }
                            } catch (Exception ex) {
                                // report a crash
                            }
                        } else {
                            // done with media player
                            mp.release();
                            mp = null;
                        }
                    }
                });

                mediaPlayer.start();
                startPlayProgressUpdater();

        }else {
            buttonPlayStop.setText(getString(R.string.play_str));
            mediaPlayer.pause();
        }
    }
    public void startPlayProgressUpdater() {
        seekBar.setProgress(mediaPlayer.getCurrentPosition());

        if (mediaPlayer.isPlaying()) {
            Runnable notification = new Runnable() {
                public void run() {
                    startPlayProgressUpdater();
                    if(seekBar.getProgress()==100){
                        for(int index=0;index<soundsRawResIds.length;index++){

                            index++;
                        }
                    }

                }
            };
            handler.postDelayed(notification,1000);
        }else{
            mediaPlayer.pause();
            buttonPlayStop.setText(getString(R.string.play_str));
            seekBar.setProgress(0);
        }
    }
}

我的 XML 代码:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <SeekBar
            android:layout_width="fill_parent"
            android:progress="0"
            android:max="100"
            android:layout_height="wrap_content"
            android:id="@+id/seekBar"/>
        <Button
            android:text="@string/play_str"
            android:textSize="15pt"
            android:textStyle="bold"
            android:onClick="playAndStop"
            android:id="@+id/ButtonPlayStop"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_marginRight="-3dp"/>
       <TextView
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:id="@+id/timeSound"
           android:textSize="30sp"
           android:text="00:00"
           />

    </LinearLayout>

Answer 1

为 mediaPlayer 设置一个 onCompletionListener。

mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
  @Override
  public void onCompletion(MediaPlayer mp) {
            //custom method to play next song
            playNextSong();        
  }
});

从数组简单示例播放。

private String[] songPaths;
private int playingPostion=0;

public void play(){
   if(mediaPlayer==null){
      mediaPlayer=new MediaPlayer();
   }else{
      mediaPlayer.reset();
   }
   //your array contains resource files.First convert them to a uri before submitting to the mediaPlayer
   String uri = "android.resource://" + getPackageName() + "/"+songPaths[playingPosition];
   mediaPlayer.setDataSource(Uri.parse(uri));
   mediaPlayer.prepare();
   mediaPlayer.start();
   //prepare your textviews and seekbar

   //prepare the player to play next song from array after completing current song
   if(playingPosition==0){
     if(songPaths.length>1){
        playingPosition++;
     }
   }else if((playingPosition+1)==songPaths.length){
        playingPosition=0;
   }else{
        playingPostion++;
   }

   mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                @Override
                public void onCompletion(MediaPlayer mp) {
                    play();
                    //do anything else you desire
                }
            });  
}

以上代码仅作为示例。使用您的线程并正确尝试 catch 语句。