一个计时器对象，更新了TextView中的所有计时器

如何解决一个计时器对象，更新了TextView中的所有计时器

我的应用程序应显示多个计时器并同时启动它们。

问题在于这些程序无法同步运行。您可以在GIF上看到这一点，可以看到它们失去了同步性。一定时间后，您会看到计时器的更新速度比其他计时器快。显示第一个计时器1，然后显示延迟的计时器2，然后显示特定的延迟计时器3。

我想创建多个计时器，每个计时器都有不同的持续时间。我想在TextView中显示这些计时器。我在%{DOCUMENT_ROOT}/.well-known/acme-challenge/的ArrayList中初始化它。然后将它们添加到MainActivity中，以便也显示它们。首先，我将经历一个for循环并为每个单独的对象执行ReyclerView方法。不幸的是，每个定时器的时间都不正确。这意味着一个计时器更快，第二个计时器更慢，依此类推。因此，每个计时器都在不同的时间启动，或者文本在不同的时间更改。

一个广告中仅包含一个计时项（例如ScheduledExecutorService） viewmodel，而不是活动中的10。虽然您可能想描绘10 时间，在用户界面中，您只需要一个计时项即可告诉您何时秒已过去。让viewmodel发出时间值的详细信息应该在用户界面中呈现的让用户界面仅显示那些时间值

上面的文本是一个答案。我该如何构建它以便只有一个计时器元素并控制时间？如何让这些计时器同步运行？每个计时器应同时更新并显示。我期待着一个答案，在此先感谢您的支持！

MainActivity

startTimer()

ModelTimer

public class MainActivity extends AppCompatActivity implements ModelTimer.MyCallback {


private RecyclerView recyclerView;
private Button button_start;
private Dialog epicDialog;

public static ArrayList<ModelTimer> timerList;
public static TimerAdapter adapter;
public static Context context;



@Override
protected void onCreate(Bundle savedInstanceState) {


    recyclerView = findViewById(R.id.recyclerview_timers);
    button_start = findViewById(R.id.button_start);

    timerList= new ArrayList<>();
    for (int i = 1; i <= 10; i++) {
        timerList.add(new Timer(i,600000 * i))); //Each timer has a different time
    }

    recyclerView.setLayoutManager(recyclerViewLayoutManager);
    adapter = new TimerAdapter(this,timerList);

    recyclerView.setAdapter(adapter);
    context = this;


    button_start.setOnClickListener(v -> {

        for (Timer timer: timerList) {
            timer.startTimer();


        });

        @Override
        public void updateMyText(int index,long time) {
            timerList.get(index-1).setTime(time);
            adapter.notifyDataSetChanged();
        }

    }






    @Override
    public void updateMyText(int index,long time) {
        timerList.get(index-1).setTime(time);
        adapter.notifyDataSetChanged();
    }
}

TimerAdapter

public class ModelTimer {


    public interface MyCallback {
        public void updateMyText(int index,long time);
    }

    private int index;
    private long time;
    private CountDownTimer mCountDownTimer;
    private boolean mTimerRunning;
    private long startTime;
    private long mTimeLeftInMillis;
    private String timeLeftFormatted;
    private MyCallback myCallback = null;


    public ModelTimer(int index,long startTimeMilliseconds,MyCallback callback) {
        this.index = index;
        this.time = startTimeMilliseconds;
        mTimeLeftInMillis = startTimeMilliseconds;
        startTime = startTimeMilliseconds;
        this.myCallback = callback;
    }


    public void startTimer() {
        mCountDownTimer = new CountDownTimer(mTimeLeftInMillis,1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                mTimeLeftInMillis = millisUntilFinished;
                updateCountDownText();
            }
            @Override
            public void onFinish() {
                mTimerRunning = false;
            }
        }.start();
        mTimerRunning = true;
    }

    public void resetTimer() {
        mCountDownTimer.cancel();
        mTimerRunning = false;
        mTimeLeftInMillis = startTime;
        timeLeftFormatted = formattedTime(startTime);
        changeText(index-1);
    }

    public void updateCountDownText() {
       //System.out.println("ID: " + getIndex() + " " + mTimeLeftInMillis);
        if(myCallback != null) {
            myCallback.updateMyText(getIndex(),mTimeLeftInMillis);
        }

    }


    private void changeText(int element) {

        String[] data = timeLeftFormatted.split(":");
        int hours  = Integer.parseInt(data[0]);
        int minutes = Integer.parseInt(data[1]);
        int seconds = Integer.parseInt(data[2]);

        int timeSeconds = seconds + 60 * minutes + 3600 * hours;
        long milliseconds = TimeUnit.MILLISECONDS.convert(timeSeconds,TimeUnit.SECONDS);
        MainActivity.countdownList.get(element).setTime(milliseconds);
        MainActivity.adapter.notifyDataSetChanged();

    }

    public static long getMilliseconds(String time) {
        String[] data = time.split(":");
        int hours  = Integer.parseInt(data[0]);
        int minutes = Integer.parseInt(data[1]);
        int seconds = Integer.parseInt(data[2]);

        int timeSeconds = seconds + 60 * minutes + 3600 * hours;
        return TimeUnit.MILLISECONDS.convert(timeSeconds,TimeUnit.SECONDS);
    }



    public static String formattedTime(long time) {
        int milliToSec = (int) (time / 1000);
        int hours = milliToSec / 3600;
        int minutes = (milliToSec / 60) % 60;
        int seconds = milliToSec % 60;
        return String.format(Locale.getDefault(),"%02d:%02d:%02d",hours,minutes,seconds);
    }

    public int getIndex() {
        return this.index;
    }

    public void setIndex(int index) {
        this.index = index;
    }

    public long getTime() { return this.time; }

    public void setTime(long time) {
        this.time = time;
    }
}

解决方法

如果需要，可以使用CountDownTimer进行尝试。看起来像这样：

public class TimerHelper {

    public interface UpdateCallback {

        /**
         * @return true if want to be updated again false otherwise
         */
        boolean secondPassedCallback();
    }

    private ArrayList<UpdateCallback> callbacksList = new ArrayList<>();

    /**
     * @param maxTime maximum of all timers
     */
    public void start(int maxTime) {

        CountDownTimer mCountDownTimer = new CountDownTimer(maxTime,1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                ArrayList<UpdateCallback> itemsToRemove=new ArrayList<>();

                for (UpdateCallback updateCallback : callbacksList) {
                    boolean wantToBeUpdated = updateCallback.secondPassedCallback(); // remove timers that reached 0
                    if (!wantToBeUpdated) {
                        itemsToRemove.add(updateCallback);
                    }
                }
                callbacksList.removeAll(itemsToRemove);
            }

            @Override
            public void onFinish() {
            }
        };
        mCountDownTimer.start();
    }


    public boolean addCallback(UpdateCallback callback) {
        return callbacksList.add(callback);
    }

    public boolean removeCallback(UpdateCallback callback) {
        return callbacksList.remove(callback);
    }

}

有了这个，只需让您的ModelTimer实现此回调并在那里进行UI更新即可。最后，在活动中将button_start OnClickListener更改为：

    button_start.setOnClickListener(v -> {
        TimerHelper t = new TimerHelper();
        for (ModelTimer timer : timerList) {
            t.addCallback(timer);
        }
    });

您可以在ReyclerView ViewHolder中而不是在ModelTimer中

chronometer.setBase(new Date().getTime());
chronometer.setOnChronometerTickListener(new OnChronometerTickListener() {
    public void onChronometerTick(Chronometer cArg) {
         long t = SystemClock.elapsedRealtime() - cArg.getBase();
         cArg.setText(DateFormat.format("HH:mm:ss",t));
    }
 });
 chronometer.start();

一个计时器对象，更新了TextView中的所有计时器

如何解决一个计时器对象，更新了TextView中的所有计时器

解决方法

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