Alarm manager triggered immediately

Question

Hi I am currently working with AlarmManager. I have written a code given below. As per code the AlarmManager should be triggered after 10 Sec, but here in my code the alarm manager triggers immediately. Please help.

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        int alarmType = AlarmManager.ELAPSED_REALTIME_WAKEUP;
        long timeOrLengthofWait = 10000;
        Intent intentToFire = new Intent(this, AlarmReciever.class);
        PendingIntent alarmIntent = PendingIntent.getBroadcast(this, 0, intentToFire, 0);
        alarmManager.set(alarmType, timeOrLengthofWait, alarmIntent);
    }
}

And My AlarmReciever Class

public class AlarmReciever extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {

        String phoneNumberReciever="5556";
        String message="Alarm Triggered";
        SmsManager sms = SmsManager.getDefault(); 
        sms.sendTextMessage(phoneNumberReciever, null, message, null, null);
        Toast.makeText(context," A message has been sent", Toast.LENGTH_LONG).show();

        Log.d("Alarm ", "Alarm Has been triggered and sms send");
    }
}

I have Already added required permissions in manifest.

Answer 1

You are using an alarm type of ELAPSED_REALTIME_WAKEUP. That means that the second parameter to set() must be the number of milliseconds from now, where now is expressed as SystemClock.elapsedRealtime().

If your goal is to have this occur 10000 milliseconds from the time you make the set() call, that set() call should be:

alarmManager.set(alarmType, SystemClock.elapsedRealtime()+timeOrLengthofWait, alarmIntent);