java – 如何在UI线程中运行此类？

我有类ScheduleTimer,它适用于日期数组.这里是：

class ScheduleTimer {

    public TextView textView;

    private Timer dateTimer;

    private Timer remainderTimer;

    private Date formatDate = new Date();

    private Date nextDate;

    private boolean remainderTimerStarted;

    private static final long REMINDER_UPDATE_INTERVAL = 1000;

    private static String[] DATES;

    private int currentIndex;

    public ScheduleTimer(final TextView t) {
        textView = t;
        dateTimer = new Timer();
    }

    public void main(String[] dates) throws ParseException {
        checkDates(dates);
        run();
    }

    private void checkDates(String[] dates) throws ParseException {
        List<String> list = new ArrayList<>();
        DateFormat format = new SimpleDateFormat("dd.MM.yyyy HH:mm",Locale.ENGLISH);
        for(String date : dates) {
            long current = System.currentTimeMillis() + 1000;
            if(format.parse(date).getTime() - current > 0) {
                list.add(date);
            }
        }
        DATES = new String[list.size()];
        list.toArray(DATES);
    }

    private void run() {
        nextDate = parseDate(DATES[currentIndex]);
        schedule();
    }

    public void schedule() {
        runSecondsCounter();
        dateTimer.schedule(new TimerTask() {

            @Override
            public void run() {

                System.out.println("Current date is:" + new Date());
                currentIndex++;
                if (currentIndex < DATES.length) {
                    nextDate = parseDate(DATES[currentIndex]);
                    System.out.println("Next date is:" + nextDate);
                    schedule();
                } else {
                    remainderTimer.cancel();
                }
            }
        },nextDate);

    }

    private Date parseDate(String nextDate) {
        Date date = null;
        DateFormat format = new SimpleDateFormat("dd.MM.yyyy HH:mm",Locale.ENGLISH);
        try {
            date = format.parse(nextDate);
        } catch (ParseException e) {
            e.printstacktrace();
        }
        return date;
    }

    private void runSecondsCounter() {
        if (remainderTimerStarted) {
            remainderTimer.cancel();
        }

        remainderTimer = new Timer();
        remainderTimer.scheduleAtFixedrate(new TimerTask() {

            @Override
            public void run() {
                remainderTimerStarted = true;
                long remains = nextDate.getTime() - new Date().getTime();
                System.out.println("Remains: " + (remains / 1000) + " seconds");
                formatDate.setTime(remains);
                textView.setText(formatDate.toString());
            }
        },REMINDER_UPDATE_INTERVAL,REMINDER_UPDATE_INTERVAL);
    }
}

如果我像Java应用程序一样运行它,而不是android,它可以正常运行,并且它会在控制台中打印出每个计数秒.但是当它在android环境中运行它时,它要么说不能从任何其他线程触及UI线程,要么它在ScheduleTimer类的方法run()中给我NullPointerException.

我正在使用它：new ScheduleTimer(textView).main(new String [] {“13.04.2015 13:59”,“13.04.2015 14:14”,“13.04.2015 14:15”});

我尝试使用AsyncTask或Handler,但可能,我做得不对.
无论如何,我需要找到使用这个类以某种方式更新我的TextView的方法.

有人可以帮我吗？如何在我的onCreateView方法中正常运行它并正确传递所需的TextView？

解决方法

完整的答案是：
你的片段：

public class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main,container,false);

            TextView textView = (TextView) rootView.findViewById(R.id.tv);

            try {
                new ScheduleTimer(textView,getActivity())
                        .main(new String[] {"13.04.2015 13:59","13.04.2015 14:14","13.04.2015 14:15"});
            } catch (ParseException e) {
                e.printstacktrace();
            }

            return rootView;
        }
    }

您的ScheduleTimer类：

class ScheduleTimer {

    public TextView textView;

    private Timer dateTimer;

    private Timer remainderTimer;

    private Date formatDate = new Date();

    private Date nextDate;

    private boolean remainderTimerStarted;

    private static final long REMINDER_UPDATE_INTERVAL = 1000;

    private static String[] DATES;

    private int currentIndex;

    private Activity activity;

    public ScheduleTimer(final TextView t,Activity a) {
        textView = t;
        activity = a;
        dateTimer = new Timer();
    }

    public void main(String[] dates) throws ParseException {
        checkDates(dates);
        run();
    }

    private void checkDates(String[] dates) throws ParseException {
        List<String> list = new ArrayList<>();
        DateFormat format = new SimpleDateFormat("dd.MM.yyyy HH:mm",Locale.ENGLISH);
        try {
            date = format.parse(nextDate);
        } catch (ParseException e) {
            e.printstacktrace();
        }
        return date;
    }

    private void runSecondsCounter() {
        if (remainderTimerStarted) {
            remainderTimer.cancel();
        }

        remainderTimer = new Timer();
        remainderTimer.scheduleAtFixedrate(new TimerTask() {

            @Override
            public void run() {
                remainderTimerStarted = true;
                long remains = nextDate.getTime() - new Date().getTime();
                System.out.println("Remains: " + (remains / 1000) + " seconds");
                formatDate.setTime(remains);

                activity.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        textView.setText(formatDate.toString());
                    }
                });

            }
        },REMINDER_UPDATE_INTERVAL);
    }
}