从服务中运行活动中的调用方法

我目前正在开发一个Android项目.

到目前为止,我已经实现了Firebase,特别是FirebaseInstanceIdService和FirebaseMessagingService:

public class FirebaseIDService extends FirebaseInstanceIdService {
private static final String TAG = "FirebaseIDService";

private Context context;

@Override
public void onTokenRefresh() {
    cOntext= getApplicationContext();
    // Get updated InstanceID token.
    String refreshedToken = FirebaseInstanceId.getInstance().getToken();
    Log.e(TAG, "Refreshed token: " + refreshedToken);

    SharedPreferences sharedPreferences = context.getSharedPreferences("token", context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPreferences.edit();
    editor.putString("token", refreshedToken);
    editor.commit();

    sendRegistrationToServer(refreshedToken);
}

/**
 * Persist token to backend.
 * @param token The new token.
 */
private void sendRegistrationToServer(String token) {
    SendRegistrationKey task = new SendRegistrationKey(context);
    task.execute(token);
}

}

public class MessagingService extends FirebaseMessagingService {

private static final String TAG = "MsgService";

/**
 * Called when message is received.
 *
 * @param remoteMessage Object representing the message received from Firebase Cloud Messaging.
 */
@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
    Log.e(TAG, "From: " + remoteMessage.getFrom());

    // Check if message contains a data payload.
    if (remoteMessage.getData().size() > 0) {
        Log.e(TAG, "Message data payload: " + remoteMessage.getData());
    }

    // Check if message contains a notification payload.
    if (remoteMessage.getNotification() != null) {
        Log.e(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());

        sendNotification(remoteMessage);
    }

    // Also if you intend on generating your own notifications as a result of a received FCM
    // message, here is where that should be initiated. See sendNotification method below.
}
// [END receive_message]

private void sendNotification(RemoteMessage remoteMessage) {
    RemoteMessage.Notification notification = remoteMessage.getNotification();
    PushNotificationManager PNManager = PushNotificationManager.getInstance(getApplicationContext());
    PNManager.buildNotification(notification.getTitle(), notification.getBody());
}

我想要实现的目标如下:

当应用程序处于后台时,我只想在通知中心发出简单通知.(这已经有效了)

但是,当应用程序处于前台并且当前正在运行时,我想要有不同的行为:我想要使用推送通知并显示警报.

但我的问题是:我如何与服务中的运行活动进行交互,或者实现预期行为的正确方法是什么？必须是一个简单的灵魂,对吗？

提前致谢