How to ensure AlarmManager survives phone restart and application kill

问题

I have an Android application where I want to send a notification to the user at a fixed time during the day

For this, I am using AlarmManager to schedule an alarm and then use that to generate notifications

But I am facing issue that if the user "Force Closed" the app, the Alarms is reset and hence I don't receive any notifications. Is this is a normal behaviour? Is there is any way out for this?

Also, the alarms also gets cancelled if the phone restarts. How do I control that? Do I need to listen to the Phone Reboot event and again schedule the alarm there? Is that the only option here?

回答1:

I have a table in my database to store all my pending alarms in case of a reboot. If the phone is rebooted I have a Service Class that resets the alarms.

private AppDatabase mDbHelper;
public class BootService extends Service {

    @Override
    public IBinder onBind(final Intent intent) {
            return null;
    }

    @Override
    public void onCreate() {
            super.onCreate();
            mDbHelper = new AppDatabase(this);
            mDbHelper.open();
    }

    @Override
    public void onStart(final Intent intent, final int startId) {
            super.onStart(intent, startId);
            LoadNotificationsFromDB();             
    }

    private void LoadNotificationsFromDB() {
            Cursor c = mDbHelper.getPendingNotifications();
            if (c.moveToFirst()) {
                    do {

                            int id = c.getInt(AppDatabase.ID_COLUMN);
                            String date = c.getString(AppDatabase.DATE_COLUMN);
                            addNotification(id, date);
                    } while (c.moveToNext());
            }
            c.close();
    }

    private void addNotification(int id, String date) {
            Intent intent = new Intent(BootService.this,    
                           NotificationBroadcastReceiver.class);

            PendingIntent mAlarmSender = PendingIntent.getBroadcast(
                            BootService.this, id, intent, 0);

            long alarmDate = Long.valueOf(date);

            AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
            am.set(AlarmManager.RTC_WAKEUP, date, mAlarmSender);
    }
}

Then Create a Receiver class:

public class BootReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {
            if ("android.intent.action.BOOT_COMPLETED".equals(intent.getAction())) {
                    Intent mServiceIntent = new Intent();
                    mServiceIntent.setAction("<package name>.BootService");
                    ComponentName service = context.startService(mServiceIntent);
                    if (null == service) {
                            // something really wrong here
                    }
            } 
    }
}

And Add the following lines to the Manifest.xml

    <receiver android:name=".BootReceiver" android:enabled="true">
            <intent-filter>
                    <action android:name ="android.intent.action.BOOT_COMPLETED"></action>
            </intent-filter>
    </receiver>
</application>
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

回答2:

You are going to need to set up something similar to this to hook on to the boot completed intent.

<receiver android:name="MyStartupIntentReceiver">
<intent-filter>
<action
  android:name="android.intent.action.BOOT_COMPLETED" />
<category android:name="android.intent.category.HOME" />
</intent-filter>
</receiver>

Once you have that you're going to need to start a service or do something in

public void onReceive(Context context, Intent intent) {
    Intent serviceIntent = new Intent();
    serviceIntent.setAction("com.yourapp.yourservice");
    context.startService(serviceIntent);
}

来源：https://stackoverflow.com/questions/11527581/how-to-ensure-alarmmanager-survives-phone-restart-and-application-kill

标签

android

alarmmanager