Android线程无法同步启动

Question

我有一个class，其中我创建了一个graphview，其中包含从一首歌曲中获取的单词以及一个mediaplayer，以便在按下按钮时播放song 。 graph一次显示1秒，因此如果我coordinates每100ms更改0.1。我应该graphview移动速度与song一样快。

只有按下按钮时，audio play graph move position才应application，发布后再返回原来的reset。现在使用我的代码，graphview正在做得很好。

唯一的问题是，一旦释放按钮后position，歌曲graph就会从第一次出现的同一mediaplayer plays audio later开始。 {1}}开始移动速度更快或button并且我不确定为什么会这样，以及每次 public class SongPlayer extends AppCompatActivity { private Viewport graphViewPort; private Handler handler; private Runnable runnable; private GraphView graph; private DataPoint[] points; private LineGraphSeries<DataPoint> series; private int seriesNr; final static double graphStartingX = -0.8; final static double graphEndingX = 0.4; private double orderNr = graphStartingX; private ImageButton playRecordButton; private Button backToSongList; private TextView songTitleTextView; private List<Pitch> pitchesList; List<List<Pitch>> wordsList; ArrayList<Audio> audioList; private int songIndex; private MediaPlayer mediaPlayer; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.song_player); Intent intent = getIntent(); String songTitle = intent.getExtras().getString("TITLE"); songIndex = intent.getExtras().getInt("INDEX"); audioList = intent.getExtras().getParcelableArrayList("AUDIOLIST"); //Get Textview and Button playRecordButton = (ImageButton) findViewById(R.id.playRecord); songTitleTextView = (TextView) findViewById(R.id.songTitle); backToSongList = (Button) findViewById(R.id.backToSongList); songTitleTextView.setText(audioList.get(songIndex).getTitle()); //Initialize pitches and words MakePitchesList listOfPithes = new MakePitchesList(); MakeWordsList listOfWords = new MakeWordsList(); pitchesList = listOfPithes.getListOfPitches(); wordsList = listOfWords.getWordsList(pitchesList); //Initialize graph graph = (GraphView) findViewById(R.id.graph); initGraph(); //ViewPort graphViewPort = graph.getViewport(); //Handler handler = new Handler(); playRecordButton.setOnTouchListener(new View.OnTouchListener() { @Override public boolean onTouch(View view, MotionEvent motionevent) { final int action = motionevent.getAction(); //If button is pressed if (action == MotionEvent.ACTION_DOWN) { Log.i("repeatBtn", "MotionEvent.ACTION_DOWN"); //Start playing audio playMedia(songIndex); //Start moving graph drawAndMoveGraph(); //If button is released, stop audio and set everything back to starting position } else if (action == MotionEvent.ACTION_UP) { Log.i("repeatBtn", "MotionEvent.ACTION_UP"); handler.removeCallbacks(runnable); graphViewPort.setMinX(graphStartingX); graphViewPort.setMaxX(graphEndingX); graph.invalidate(); orderNr = graphEndingX; stopAudio(); }//end else return false; } //end onTouch }); //end b my button backToSongList.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(SongPlayer.this, MainActivity.class); startActivity(intent); } }); // StrictMode.enableDefaults(); } //Move the graph by 0.1 every 100ms private void drawAndMoveGraph(){ runnable = new Runnable() { public void run() { System.out.println(orderNr); graphViewPort.setMinX(orderNr); graphViewPort.setMaxX(orderNr + 1); graph.invalidate(); if(pitchesList.size() != orderNr){ orderNr = orderNr + 0.1; } handler.postDelayed(this, 100); } }; runnable.run(); } //Initialize graph private void initGraph(){ for (int i = 0; i < wordsList.size(); i++) { seriesNr = 0; points = new DataPoint[wordsList.get(i).size()]; for (Pitch pitch: wordsList.get(i)) { points[seriesNr] = new DataPoint(pitch.getOccuranceTime(), pitch.getPitch()); seriesNr++; } series = new LineGraphSeries<>(points); series.setThickness(15); graph.addSeries(series); } //VocalTestPoints PointsGraphSeries<DataPoint> series = new PointsGraphSeries<>(new DataPoint[] { new DataPoint(0, 50), new DataPoint(0, 75), new DataPoint(0, 100), new DataPoint(0, 125), new DataPoint(0, 150), new DataPoint(0, 175), new DataPoint(0, 200), new DataPoint(0, 225), new DataPoint(0, 250), new DataPoint(0, 275), }); series.setSize(5); series.setColor(Color.YELLOW); graph.addSeries(series); // set manual X bounds graph.getViewport().setYAxisBoundsManual(true); graph.getViewport().setMinY(-50); graph.getViewport().setMaxY(400); graph.getViewport().setXAxisBoundsManual(true); graph.getViewport().setMinX(graphStartingX); graph.getViewport().setMaxX(graphEndingX); //mitu korraga näeb graph.getViewport().setScrollable(true); } //Play Audio private void playMedia(int songIndex){ StorageUtil storage = new StorageUtil(getApplicationContext()); storage.storeAudio(audioList); storage.storeAudioIndex(songIndex); mediaPlayer = new MediaPlayer(); //Reset so that the MediaPlayer is not pointing to another data source mediaPlayer.reset(); mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); try { mediaPlayer.setDataSource(storage.loadAudio().get(storage.loadAudioIndex()).getData()); } catch (IOException e) { e.printStackTrace(); } mediaPlayer.prepareAsync(); mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() { @Override public void onPrepared(MediaPlayer mp) { mediaPlayer.start(); } }); } private void stopAudio(){ mediaPlayer.stop(); mediaPlayer.release(); } } 被按下时我应该怎么做才能同时运行。

threads, runnables and async's

我不知道从哪里开始。我一直在尝试不同的graphview，但结果总是一样的。

只是为了澄清{{1}}看起来像这样：