Question

我有一个名为BroadcastReceiver的{{1}} AlarmReceiver s“警报有效”。我正在尝试设置重复的Toast以在5:45和17:30触发PendingIntent，但是在启动应用程序几秒钟后我看到“闹钟工作”。为什么AlarmReceiver会立即发送？

PendingIntent

AlarmReceiver：

 public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Calendar cal1 = Calendar.getInstance();
        cal1.set(Calendar.HOUR_OF_DAY, 05);
        cal1.set(Calendar.MINUTE, 45);
        cal1.set(Calendar.SECOND, 00);

        Calendar cal2 = Calendar.getInstance();
        cal2.set(Calendar.HOUR_OF_DAY, 17);
        cal2.set(Calendar.MINUTE, 30);
        cal2.set(Calendar.SECOND, 00);

        Intent intent = new Intent(this, AlarmReceiver.class);

        PendingIntent pi = PendingIntent.getBroadcast(getApplicationContext(), 0, intent,      PendingIntent.FLAG_UPDATE_CURRENT);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, cal1.getTimeInMillis(),cal2.getTimeInMillis(), pi);


        Toast.makeText(this, "Alarm set", Toast.LENGTH_LONG).show();

    }


}

Answer 1

但是在我的应用程序启动几秒后，我看到“闹钟工作”。

我相信你收到第一个警报就好了。

但你相信它不会重复。这是错误的，将重复......每〜43年一次。您错误地使用了setRepeating的第三个参数，请尝试：

Calendar cal1 = Calendar.getInstance(); // Now
cal1.add(Calendar.SECONDS, 5); // Change to five seconds from now

alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, 
        cal1.getTimeInMillis(), 
        10000, /* Repeat every 10 seconds */ 
        pi);

第三个参数是 interval 。此代码创建一个在5秒内熄灭的警报，然后每10秒重复一次。通过使用cal2，您不小心将间隔设置为将近43年。

要设置两个不同的闹钟，请使用：

Calendar cal1 = Calendar.getInstance();
cal1.set(Calendar.HOUR_OF_DAY, 05);
cal1.set(Calendar.MINUTE, 45);
cal1.set(Calendar.SECOND, 00);

Calendar cal2 = Calendar.getInstance();
cal2.set(Calendar.HOUR_OF_DAY, 17);
cal2.set(Calendar.MINUTE, 30);
cal2.set(Calendar.SECOND, 00);

// Test if the times are in the past, if they are add one day
Calendar now = Calendar.getInstance();
if(now.after(cal1))
    cal1.add(Calendar.HOUR_OF_DAY, 24);
if(now.after(cal2))
    cal2.add(Calendar.HOUR_OF_DAY, 24);

// Create two different PendingIntents, they MUST have different requestCodes
Intent intent = new Intent(this, AlarmReceiver.class);
PendingIntent morningAlarm = PendingIntent.getBroadcast(getApplicationContext(), 0, intent, 0);
PendingIntent eveningAlarm = PendingIntent.getBroadcast(getApplicationContext(), 1, intent, 0);

// Start both alarms, set to repeat once every day
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, cal1.getTimeInMillis(), DateUtils.DAY_IN_MILLIS, morningAlarm);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, cal2.getTimeInMillis(), DateUtils.DAY_IN_MILLIS, eveningAlarm);

Answer 2

正如Sam's post所述，您没有使用正确的triggerAtMillis和intervalMillis。我认为你告诉它在当天早上5点触发，这可能在过去，在这种情况下，documentation表示

Calendar cal1 = Calendar.getInstance();
cal1.add(Calendar.HOUR, 5);
cal1.add(Calendar.MINUTE, 45);

long interval = 17 * 60 * 60 * 1000; // 17 hours converted to milliseconds
interval += 30 * 60 * 1000; // 30 minutes converted to milliseconds

Intent intent = new Intent(this, TestAlarmReceiver.class);
PendingIntent pi = PendingIntent.getBroadcast(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, cal1.getTimeInMillis(), interval, pi);

可能是您想要做的事情。

编辑（更多解释）：

cal1.add(Calendar.HOUR, 5);获取当前日期和时间并将其增加5小时，因此结果是重复PendingIntent将从此日期的当前时间开始5小时45分钟。并且interval表示它将从那时起每隔17小时30分钟发送第二个及以后的PendingItent（此时距离现在为5小时45分钟）。

如果您想将开始时间设置为早上5:45，但不希望立即发送（除非恰好是当前上午5:45）。那么你会想要设置：

cal1.set(Calendar.HOUR, 5);
cal1.set(Calendar.MINUTE, 45);
cal1.set(Calendar.SECOND, 0);

// Current time is after 5:45 am, don't start until tomorrow at 5:45
if (Calendar.getInstance().after(cal1))
    cal1.add(Calendar.DAY_OF_YEAR, 1)

或者，您可以计算从该时间开始的时间间隔，以确定它将在下一次触发，假设它已经在5:45启动，但这需要更多的工作来计算。

alarmmanager 2次

2 个答案: