警报管理器延迟警报响铃的问题

Question

我遇到了一个问题，当我设置时间时，闹钟响起有延迟。有时闹钟也会提早响起。我不确定我哪里做错了。希望有人能帮我解决这个问题。

public void showHourPicker(View view) {


    currentHour = calendar.get(Calendar.HOUR_OF_DAY);
    currentMinute = calendar.get(Calendar.MINUTE);

    timePickerDialog = new TimePickerDialog(MainActivity.this, android.R.style.Theme_Holo_Light_Dialog_NoActionBar, new TimePickerDialog.OnTimeSetListener() {
        @Override
        public void onTimeSet(TimePicker timePicker, int hourOfDay, int minutes) {

            if (hourOfDay >= 12) {
                amPm = "PM";
            } else {
                amPm = "AM";
            }
            txtTime.setText(String.format("%02d:%02d ", hourOfDay, minutes) + amPm);

            calendar.set(Calendar.HOUR_OF_DAY,hourOfDay);
            calendar.set(Calendar.MINUTE,minutes);
        }

    }, currentHour, currentMinute, false);

    timePickerDialog.setTitle(" Your Expected Time : " + exp.getText());
    timePickerDialog.getWindow().setBackgroundDrawableResource(android.R.color.transparent);
    timePickerDialog.show();

    startAlarm(calendar);

}

public void startAlarm(Calendar calendar) {

    AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(this, MyBroadcastReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),AlarmManager.INTERVAL_DAY,pendingIntent);

}

Answer 1

这是 AlarmManager.setRepeating 中描述的预期行为：

As of API 19, all repeating alarms are inexact. If your application needs precise delivery times then it must use one-time exact alarms, rescheduling each time as described above.

Answer 2

setRepeating 等于 API 上面的 setInexactRepeating 19. 如果你想在固定的时间间隔后准确地重复它，那么在你的广播接收器中使用 handler.postDelayed。我附上了我的广播接收器代码之一，实现相同

public class AlertReceiver extends BroadcastReceiver {
private MediaPlayer alarmRinger;
@Override
public void onReceive(Context context, Intent alarmIntent) {
   alarmRinger = MediaPlayer.create(context, R.raw.alarmringer);
   runnable.run();
   }
private final Handler handler = new Handler();
private final Runnable runnable = new Runnable() {
    @Override
    public void run() {
        alarmRinger.start();
        handler.postDelayed(this, 3600000);//Change the timing accordingly in MS 
    }
};

}

这里我的 AlarmManager 触发广播接收器，然后广播接收器触发 MediaPlayer 来创建用于播放声音的 mediaPlayer 并且还触发 runnable.run() 导致 Runnable至运行。当运行nable 被触发时，mediaPlayer 运行s 并播放声音然后 handler.postDelayed 设置为在 1 小时（3600000 毫秒）内再次重复 Runnable 的任务，这是无限重复或直到你杀死运行nable.

警报管理器延迟警报响铃的问题

problem with alarm manager delay in alarm ringing

android

android-layout

timepicker

android-timepicker