AlarmManager不添加新警报，或不触发接收器 [英] AlarmManager not adding new Alarms, or not triggering receiver

问题描述

我目前正在开发一个使用Android的AlarmManager的应用程序。我正在尝试向AlarmManager添加新警报，但是经过数小时尝试各种操作并检查SO上的各种线程之后，我仍然处于困境。我的代码有任何问题吗？

I'm currently developing an application which makes use of Android's AlarmManager. I'm trying to add a new alarm to the AlarmManager, but after several hours of trying various things and checking various threads on SO, I'm still at a brick wall. Are there any problems with my code?

主要活动-saveAlarm（）函数

/**
 * Saves the current alarm. Adds to the database if it doesn't already exist, or updates if it does.
 * Also sets alert with AlarmManager.
 */
public void saveAlarm() {
    // Create Database instance
    DbHandler db = new DbHandler(getApplicationContext());

    if(alarm.getId() == -1) {
        // Saving a new alarm
        db.open();
        alarm.setId(db.addAlarm(alarm));
        db.close();
    }
    else {
        db.open();
        db.updateAlarm(alarm);
        db.close();
    }

    // Create the wakeup intent
    Intent intent = new Intent(this, AlarmReceiver.class);
    intent.putExtra("alarm_id", alarm.getId());

    // Create the Pending Intent
    PendingIntent sender = PendingIntent.getBroadcast(this, AlarmPlayer.REQUEST_ALARM + alarm.getId(), intent, PendingIntent.FLAG_UPDATE_CURRENT);

    // Debug
    Calendar now = Calendar.getInstance();
    long dTime  = alarm.getNextAlarmTime().getTimeInMillis() - now.getTimeInMillis();
    Log.d(TAG, "Setting alarm for " + (dTime / 1000) + " seconds time");

    // Add to Android Alarm Manager
    AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
    am.set(AlarmManager.RTC_WAKEUP, alarm.getNextAlarmTime().getTimeInMillis(), sender);    
}

我已确认将正确的时间传递给 am .set （请参见上面的调试部分）。

I've verified that the correct time is being passed into am.set (see the debug section above it).

AlarmReceiver.class

/**
* This class listens out for broadcasts from AlarmManager
* and launches the AlarmPlayer activity accordingly.
* @author Michael
*
*/
public class AlarmReceiver extends BroadcastReceiver {

     @Override
    public void onReceive(Context c, Intent intent) {
        Log.d("RSS Alarm", "Waking up alarm");
            // Launch the AlarmPlayer activity
        Intent i = new Intent(c, AlarmPlayer.class);
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        c.startActivity(i);
    }

}

---

我还在AndroidManifest.xml中设置了< receiver android：process =：remote android：name = AlarmReceiver /> 。我不知道是什么原因导致了这个问题，但是仍然在发生。任何帮助将不胜感激，在此先感谢您。

---

I also have <receiver android:process=":remote" android:name="AlarmReceiver" /> set up in AndroidManifest.xml. I have no idea what's causing this problem, but it's happening nonetheless. Any help would be greatly appreciated, many thanks in advance.

编辑1
将时区更改为UTC似乎无法解决任何问题，无论如何我的日历似乎都默认为UTC。当前代码：

Edit 1 Changing the timezone to UTC doesn't seem to solve anything, my calendar seems to default to UTC regardless. Current code:

// Debug
Calendar now = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
long dTime  = alarm.getNextAlarmTime().getTimeInMillis() - now.getTimeInMillis();
Log.d(TAG, "Setting alarm for " + (dTime / 1000) + " seconds time");

// Add to Android Alarm Manager
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
Log.d(TAG, "Timezone offset is " + TimeZone.getDefault().getRawOffset());
Log.d(TAG, "UTC time is currently " + Calendar.getInstance(TimeZone.getTimeZone("UTC")).getTimeInMillis() / 1000);
am.set(AlarmManager.RTC_WAKEUP, (alarm.getNextAlarmTime().getTimeInMillis() - TimeZone.getDefault().getRawOffset()), sender);

推荐答案

是否可能是 AlarmManager.set（AlarmManager.RTC_WAKEUP，...）需要UTC时间吗？如果您设置本地时间并且不适应UTC，则可能会导致问题。简而言之，警报可能已正确添加，但除非您的时区为UTC，否则不会在您期望的时间触发。

Is this possibly a case that AlarmManager.set(AlarmManager.RTC_WAKEUP, ...) needs the time in UTC? This causes problems if you're setting a 'local time' and don't adjust to UTC. In short, the alarm may be being properly added but it doesn't trigger when you expect it unless your time-zone is UTC.

从文档中...

公共静态最终int RTC_WAKEUP，因为：API级别1

public static final int RTC_WAKEUP Since: API Level 1

系统中的警报时间.currentTimeMillis（）（ UTC的挂钟时间），它将在设备关闭时唤醒设备。

Alarm time in System.currentTimeMillis() (wall clock time in UTC), which will wake up the device when it goes off.

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