Android Studio 媒体播放器在定向后不会停止

Question

如果我改变手机的方向，音乐会继续播放，这很好，但也不会暂停或停止

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_current_music);

        musicState = String.valueOf(player.getState());

        if (savedInstanceState != null)
        {
            musicState = savedInstanceState.getString("State");

        }

        player.state = MP3Player.MP3PlayerState.valueOf(musicState);

    }


  @Override
    public void onSaveInstanceState(Bundle outState)
    {
        super.onSaveInstanceState(outState);
        outState.putInt("Red", r);
        outState.putInt("Green", g);
        outState.putInt("Blue", b);
        outState.putFloat("SPEED", playbackspeed);
        outState.putInt("PROGRESS", progressUpdate);
        outState.putInt("Update", updateIncrement);
        outState.putInt("Duration", duration);
        outState.putString("State", musicState);

    }


    public void onMusicBackClick ( View v ) {
        Log. d (" g53mdp ", " button pressed !") ;


        Intent intent = new Intent(CurrentMusic.this, MainActivity.class);
        player.stop();
        intent.putExtra("Red", r);
        intent.putExtra("Green", g);
        intent.putExtra("Blue", b);
        intent.putExtra("SPEED", playbackspeed);

        startActivity(intent);
        finish();
    }

    public void onPlayClick (View v)
    {
        Log.d("MP3 Player", "Music Play button pressed");
        if(player.getState() == MP3Player.MP3PlayerState.PAUSED)
        {
            player.play();
            musicState = String.valueOf(player.getState());
        }
        else if(player.getState() == MP3Player.MP3PlayerState.PLAYING)
        {
            player.pause();
            musicState = String.valueOf(player.getState());
        }
        else
        {
            player.load(musicURL, playbackspeed);
            musicState = String.valueOf(player.getState());

            updateIncrement = player.getDuration()/100;
            duration = player.getDuration();
            musicProgress = findViewById(R.id.p_musicProgress);
            musicProgress.setMax(duration);

            progress = player.getProgress();
            timer.scheduleAtFixedRate(timerTask = new TimerTask(){
                @Override
                public void run() {
                    progress = player.getProgress();
                    progressUpdate = progress;
                    musicProgress.setProgress(progress);
                }
            }, 0, updateIncrement);
        }
    }

    public void onPauseClick (View v)
    {
        Log.d("MP3 Player", "Music pause button pressed");
        if(player.getState() == MP3Player.MP3PlayerState.PLAYING)
        {
            player.pause();
        }
    }
    public void onStopClick (View v)
    {
        Log.d("MP3 Player", "Music stop button pressed");
        if(player.getState() == MP3Player.MP3PlayerState.PAUSED || player.getState() == MP3Player.MP3PlayerState.PLAYING)
        {
            player.stop();
        }
        player.stop();
    }

我认为只需将值转换为字符串，然后提取它并将其放回去就可以了，但是如果您播放媒体文件并调整手机方向，它几乎会变得异常

我正在打印状态，并检查每次交互下的每个状态，甚至在定向后重新创建活动后，它会说并告诉我它实际上已停止，但它仍然是如何玩的??????

Answer 1

您的问题是，重新创建活动时，对 MP3 播放器实例的引用不会持续存在，但由于它正在播放音乐，因此仍然存在于后台。在 Activity 生命周期中持久保存任何内容的正确方法是使用 ViewModel，您应该创建一个并在其中存储您的 MP3 播放器实例。