java - MediaPlayer 错误 - getCurrentPosition

Question

请教我如何解决 MediaPlayer 错误。我有 Mediaplayer、MediaController 和 listview。当我触摸列表时，歌曲会从 MediaController 开始，但是当我触摸 keycode_home 并重新启动我的应用程序时，会发生错误。这是我的代码和错误。

    java.lang.RuntimeException: Unable to resume activity {}: 
    java.lang.IllegalStateException
    Caused by: java.lang.IllegalStateException at android.media.MediaPlayer.getCurrentPosition(Native Method)


    int si[]={R.raw.sample1,R.raw.sample2,R.raw.sample3};
    onCreate

    ItemBean IB1 = new ItemBean();
    IB1.setName("sample1");
    IB1.setUrl("http~");

    ItemBean IB2 = new ItemBean();
     IB2.setName("sample2");
    IB2.setUrl("http~");

    ItemBean IB3 = new ItemBean();
    IB3.setName("sample3");
    IB3.setUrl("http~");

    List<ItemBean> list = new ArrayList<ItemBean>();
    list.add(IB1);
    list.add(IB2);
    list.add(IB3);

    mp = new MediaPlayer();
    controller = new MediaController(this);
    controller.setAnchorView(findViewById(R.id.mediaController));
    controller.setMediaPlayer(this);

    list2 = (ListView) findViewById(R.id.song_list);
    SonglistAdapter_test adapter = new SonglistAdapter_test(getApplicationContext(),list);
    list2.setAdapter(adapter);
    list2.setOnItemClickListener(this);
     }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,long id) {

    try {
        mp.reset();
        mp.release();
        mp = MediaPlayer.create(SongsActivity.this,si[position]);
    } catch (Exception e) {}

    mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {

        @Override
        public void onPrepared(MediaPlayer mediaPlayer) {
            handler.post(new Runnable() {
                @Override
                public void run() {
                    controller.setEnabled(true);
                    controller.show(mp.getDuration());
                    mp.start();
                    try {
                        Method m = android.widget.MediaController.class.getDeclaredMethod("updatePausePlay");
                        m.setAccessible(true);
                        m.invoke(controller);
                    } catch (Exception e) {
                    }
                }
            });
         }
        });
       }
    @Override
    public void start(){
    mp.start();    }

    @Override
    public void pause(){
    mp.pause();   }

    @Override
    public int getDuration(){
    return mp.getDuration();  }

    @Override
    public int getCurrentPosition(){
    return mp.getCurrentPosition(); }

    @Override
    public void seekTo(int pos){
    mp.seekTo(pos);  }

    @Override
    public boolean isPlaying(){
    return mp.isPlaying(); }

    @Override
    public int getBufferPercentage(){
    return 0; }

    @Override
    public boolean canPause(){
    return true;    }

    @Override
    public boolean canSeekBackward(){
    return true;    }

    @Override
    public boolean canSeekForward(){
    return true;    }

    @Override
    public int getAudioSessionId(){
    return 0;    }


    @Override
    protected void onPause(){
    super.onPause();
    }

    @Override
    protected void onResume(){
    super.onResume();
    }

    @Override
    protected void onStop(){
    super.onStop();
    controller.hide();
    mp.stop();
    mp.release();
    }

    @Override
    public void onRestart(){
    super.onRestart();
    controller.show();
    }

    @Override
    protected void onDestroy(){
    super.onDestroy();
      finish();
    }

    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
    if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
        finish();
    }
    return super.dispatchKeyEvent(event);
    }

Answer 1

问题出在您的 onStop() 方法中 - 您正在那里释放媒体播放器，并且在 onRestart() 期间显示 Controller 之前没有重新创建它。 onStop() 方法与 onDestroy() 不同 - onStop() 并不意味着您的 Activity 一定会运行恢复时再次onCreate()。

您应该看看 Activity Lifecycle更好地了解这些事件何时发生。