Question

尝试使用Pending Intent设置多个警报，但是警报不会在正确的时间内广播。可能是什么导致了这个？

public void clicker (View view)
{
    Calendar calendar = Calendar.getInstance();
    int hour = calendar.get(Calendar.HOUR_OF_DAY);
    int minute = calendar.get(Calendar.MINUTE);
    TimePickerDialog mTimePicker;
    mTimePicker = new TimePickerDialog(AddAlarm.this,
            new TimePickerDialog.OnTimeSetListener() {
                @Override
                public void onTimeSet(TimePicker timePicker,
                                      int selectedHour, int selectedMinute) {
                    Calendar calendar = Calendar.getInstance();
                    calendar.set(Calendar.HOUR_OF_DAY, selectedHour);
                    calendar.set(Calendar.MINUTE, selectedMinute);

                    int c_hour,c_min;
                    String format;
                    c_hour=selectedHour;
                    c_min=selectedMinute;

                    if (c_hour == 0) {
                        c_hour += 12;
                        format = "AM";
                    } else if (c_hour == 12) {
                        format = "PM";
                    } else if (c_hour > 12) {
                        c_hour -= 12;
                        format = "PM";
                    } else {
                        format = "AM";
                    }

                    String formatTime = String.format("%02d : %02d %s", c_hour, c_min, format);

                    TextView dimple = (TextView)findViewById(R.id.timeText);
                    dimple.setText(formatTime);
                    setAlarm(calendar);

                }
            }, hour, minute, false);// Yes 24 hour time
    mTimePicker.setTitle("Select Time");
    mTimePicker.show();

}

private void setAlarm(Calendar targetCal)
{


    Intent alarmintent = new Intent(AddAlarm.this, AlarmReceiver.class);
    PendingIntent sender = PendingIntent.getBroadcast(AddAlarm.this, pen, alarmintent, PendingIntent.FLAG_ONE_SHOT);
    AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
    alarmManager.set(AlarmManager.RTC_WAKEUP, targetCal.getTimeInMillis(), sender);


}

这就是我设置闹钟的方法，还有待处理的意图被设置为系统时间，以ms为单位，logcat中没有警告或错误，报警工作正常，唯一的问题是没有及时，预计一到两分钟延迟？有什么建议吗？

Answer 1

在Calendar.getInstance();中使用onTimeSet后使用calendar.setTimeInMillis(System.currentTimeMillis());

也许这会有所帮助。还要确保在多个警报的情况下对待处理意图使用不同的requestCodes

Answer 2

自API级别19以来，警报默认不准确。你可以改用setExact（）方法。

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
     am.setExact(AlarmManager.RTC_WAKEUP, targetCal.getTimeInMillis(), sender);
} else {
     am.set(AlarmManager.RTC_WAKEUP, targetCal.getTimeInMillis(), sender;
}

您可以在此处找到更多信息： http://developer.android.com/reference/android/app/AlarmManager.html#setExact%28int,%20long,%20android.app.PendingIntent%29

待定意图导致延迟

2 个答案: