android - AlarmManager 不适用于服务？

Question

几秒钟后我需要启动服务。但是 onStartCommand 方法不会被调用。我用 API 级别 26 和 API 级别 24 测试它，但似乎不起作用。

public class MyService extends Service {
    @Override
    public void onCreate() {
        setAlarm(2, 10 * 1000);
    }


    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        LogUtil.d(LOGTAG, "onStartCommand()...");
        return super.onStartCommand(intent, flags, startId); ;
    }

    private void setAlarm(int req, long interval) {
        LogUtil.d(LOGTAG, "setAlarm()...");
        AlarmManager am = (AlarmManager) this
                .getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent();
        PendingIntent pendingIntent = PendingIntent.getService(this, req,
                intent, PendingIntent.FLAG_ONE_SHOT);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            am.setExactAndAllowWhileIdle(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + interval, pendingIntent);
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            am.setExact(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + interval, pendingIntent);
        } else {
            am.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + interval, pendingIntent);
        }
    }
}