java - TimerTask 已经安排好了

Question

我有一个播放本地音频文件的 MediaPlayer 对象。我正在使用 TimerTask 在播放音频时更新 TextView 上 SeekBar 和文本的位置。

只有一个按钮。当用户按下按钮时，音频开始。当他们第二次按下时，音频停止。当他们第三次按下它再次开始播放时，应用程序崩溃并出现错误

'causedby: TimerTask is scheduled already and InvocationTargetException'.

这是我的代码:

    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

请试试这个代码块:

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...
    }
}