Question

我想在我的Android App中实现多个计时器，每个计时器独立于另一个计时器，并且来自App生命周期。

使用这些运行计时器，我想：

在专门的活动中展示所有这些
对于每个计时器，让用户可以删除它，添加1分钟，暂停它
保持它们正常运行，并在计时器到达零时发送音频通知，即使用户已关闭应用程序
使用广播接收器，我每秒更新剩余秒数的状态

我的问题是如何更好地实现多线程？如何设法与正在运行的线程进行通信？

我想创建一些非常接近原生Android计时器应用的东西。

以下是我每次添加一个计时器时创建新线程的方法（但是一旦启动计时器我无法与线程通信）

private final class ServiceHandler extends Handler {


        public ServiceHandler(Looper looper) {
            super(looper);

        }

        @Override
        public void handleMessage(Message msg) {
            // Normally we would do some work here, like download a file.
            // For our sample, we just sleep for 5 seconds.
            try {
                showCountDownTimer(enteredTimeFormatted);
                showNotification(nameOfFood, id_food);
                timer.start();
            } catch (Exception e) {
                // Restore interrupt status.
                Thread.currentThread().interrupt();
            }
            // Stop the service using the startId, so that we don't stop
            // the service in the middle of handling another job
            stopSelf(msg.arg1);
        }
    }



private void showCountDownTimer(long number) {
        timer = new CountDownTimer(number, 1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                timeLeft = millisUntilFinished;
                normalTime = String.format(
                        "%02d:%02d:%02d",
                        TimeUnit.MILLISECONDS.toHours(timeLeft),
                        TimeUnit.MILLISECONDS.toMinutes(timeLeft) -
                                TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(timeLeft)),
                        TimeUnit.MILLISECONDS.toSeconds(timeLeft) -
                                TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(timeLeft)));
                Log.i(LOG_TAG, "time left = " + normalTime);
                counter = millisUntilFinished / 1000;
                updateNotification(nameOfFood, id_food);

                Intent timerInfoIntent = new Intent(TIME_INFO);
                timerInfoIntent.putExtra("VALUE", normalTime);
                LocalBroadcastManager.getInstance(NotificationService.this).sendBroadcast(timerInfoIntent);

            }

            @Override
            public void onFinish() {
                counter = 0;
                readyNotification(nameOfFood, id_food);

                Intent timerInfoIntent = new Intent(TIME_INFO);
                timerInfoIntent.putExtra("VALUE", "Dish is ready!");
                LocalBroadcastManager.getInstance(NotificationService.this).sendBroadcast(timerInfoIntent);
            }
        };
    }

Answer 1

使用loopers和handlers。您可能会发现此文章有用：https://developer.android.com/training/multiple-threads/create-threadpool.html

多个线程与计时器

1 个答案: