TimerTask已經安排好了

Question

我有一個播放本地音頻文件的MediaPlayer對象。 我正在使用TimerTask在播放音頻時更新SeekBar的位置和TextView上的文本。

有一個按鈕。 當用戶按下按鈕時音頻開始。 當他們第二次按下它時音頻停止。 當他們第三次按下它再次開始播放時，應用程序會因錯誤而崩潰

'causedby: TimerTask is scheduled already and InvocationTargetException'.

這是我的代碼：

    public void onAudioClicked(View v) {
    if (mainPlayer == null) {
        mainPlayer = MediaPlayer.create(this, R.raw.session1);
        // Get audio duration and set textview
        int d = mainPlayer.getDuration();
        TextView t = (TextView)findViewById(R.id.totalTime);
        t.setText(String.format("%d:%d", 
                TimeUnit.MILLISECONDS.toMinutes(d),
                TimeUnit.MILLISECONDS.toSeconds(d) - 
                TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(d))));

        sb.setProgress(0);
        sb.setMax(mainPlayer.getDuration());
        mainPlayer.start();
        timer = new Timer();
        timer.schedule(task, 1000);
    } else {
        mainPlayer.stop();
        mainPlayer.release();
        mainPlayer = null;
        timer.cancel();
        task.cancel();
        timer = null;
    }
}

    TimerTask task = new TimerTask(){
    public void run(){
        int currentPosition = 0;
        int total = mainPlayer.getDuration();
        sb.setMax(total);
        while (mainPlayer != null && currentPosition < total) {
            try {
                Thread.sleep(1000);
                currentPosition = mainPlayer.getCurrentPosition();
                runOnUiThread(updateControlsRunnable);
            } catch (InterruptedException e) {
                return;
            } catch (Exception e) {
                return;
            }
            sb.setProgress(currentPosition);
        }

    }
};

final Runnable updateControlsRunnable = new Runnable () {
    public void run(){
        int d = mainPlayer.getCurrentPosition();
        TextView t = (TextView)findViewById(R.id.currentTime);
        t.setText(String.format("%d:%d", 
                TimeUnit.MILLISECONDS.toMinutes(d),
                TimeUnit.MILLISECONDS.toSeconds(d) - 
                TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(d))));
        }
};

Answer 1

請嘗試此代碼塊：

sb.setProgress(0);
sb.setMax(mainPlayer.getDuration());
mainPlayer.start();
timer = new Timer();
MyTask task=new MyTask();
timer.schedule(task,0, 1000);

private class MyTask extends TimerTask {
    public void run() {
        //Your code...
    }
}