Question

我有一个小部件即时尝试使用计时器更新TextView：

    public void onUpdate(Context context, final AppWidgetManager appWidgetManager, int[] appWidgetIds) {
    final int N = appWidgetIds.length;

    for (int i = 0; i < N; i++) {
        final int appWidgetId = appWidgetIds[i];

        Intent clockIntent = new Intent(context, DeskClock.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, clockIntent, 0);

        final RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.digitalclock);
        views.setOnClickPendingIntent(R.id.rl, pendingIntent);

        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {

            @Override
            public void run() {
                java.util.Date noteTS = Calendar.getInstance().getTime();
                String time = "kk:mm";
                String date = "dd MMMMM yyyy";

                views.setTextViewText(R.id.tvTime, DateFormat.format(time, noteTS));
                views.setTextViewText(R.id.tvDate, DateFormat.format(date, noteTS));
                appWidgetManager.updateAppWidget(appWidgetId, views);
            }
        }, 0, 1000);// Update textview every second

    }
}

问题是，它只会更新一次，之后再也不会。我哪里错了？

Answer 1

您应该使用Handler，从时间任务中对UI线程进行操作。

Timer timer = new Timer();
    timer.scheduleAtFixedRate(new TimerTask() {

        @Override
        public void run() {

              handler.post(new Runnable() {
                        public void run() {
                //Your code here
             }});
        }
    }, 0, 1000);// Update textview every second

此外，您应该像on this（

）一样在onCreate（）中启动Handler

handler = new Handler（）;

Answer 2

    int _count=0;
    _tv = (TextView) findViewById( R.id.textView1 );
    _tv.setText( "red" );
    _t = new Timer();

    _t.scheduleAtFixedRate( new TimerTask() {
            @Override
            public void run() {
                _count++;

                runOnUiThread(new Runnable() //run on ui thread
                 {
                  public void run() 
                  { 
                     _tv.setText(""+_count);
                 }
                 });
            }
        }, 1000, 1000 );

小部件更新TextView计时器无法正常工作

2 个答案: