动态注册的 BroadcastReceiver 实例没有触发？

Question

I've been trying to find the problem here, but I can't seem to... my onReceive doesn't seem to get called, here's what I have:

public abstract class NoUpdatesTimer extends BroadcastReceiver {
    private Context context;
    private PendingIntent pendingIntent;

    public NoUpdatesTimer(Context context) {
        this.context = context;
        Intent intent = new Intent(Constants.ALARM_NO_LOC_UPDATES);
        pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 0);
        context.registerReceiver(this, new IntentFilter(Constants.ALARM_NO_LOC_UPDATES));
    }

    public void scheduleCheck(long delayMillis) {
        AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
        alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + delayMillis, pendingIntent);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        ...
    }
}

With some debugging, I verified that scheduleChecking is called but the onReceive method is not called. I also tried to trigger this code from a shell, using:

adb shell am broadcast -a rsg.ms.7

(where Constants.ALARM_NO_LOC_UPDATES is "rsg.ms.7").

Can you tell me what to change so onReceive gets called?

Answer 1

Using the application context instead of the passed in service context seems to make it work, not sure why:

public abstract class NoUpdatesTimer extends BroadcastReceiver {
    private Context context;
    private PendingIntent pendingIntent;

    public NoUpdatesTimer(Context context) {
        this.context = context.getApplicationContext();
        Intent intent = new Intent(Constants.ALARM_NO_LOC_UPDATES);
        pendingIntent = PendingIntent.getBroadcast(this.context, 0, intent, 0);
        this.context.registerReceiver(this, new IntentFilter(Constants.ALARM_NO_LOC_UPDATES));
    }

    public void scheduleCheck(long delayMillis) {
        AlarmManager alarmManager = (AlarmManager)this.context.getSystemService(Context.ALARM_SERVICE);
        alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + delayMillis, pendingIntent);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        ...
    }
}

Answer 2

The nature of PendingIntent is bound relatively to ApplicationContext . for example its usage with Widgets where the broadcast is outside the application. so when you're getting broadcast from PendingIntent in PendingIntent.getBroadcast you have to provide the application context not the lower layers. I had the same issue once and it took me a whole day to figure this out.