从服务调用正在运行的活动中的方法

Question

我目前正在做一个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());
}

我想要实现的是以下几点：

当应用程序在后台运行时，我只想在通知中心有一个简单的通知。(这已经在工作了(

但是，当应用程序处于前台且当前正在运行时，我希望具有不同的行为：我想使用推送通知并改为显示警报。

但我的问题是：如何与服务中的正在运行的活动进行交互，或者实现预期行为的正确方法是什么？这一定是一个简单的灵魂，对吧？

提前致谢

Answer 1

在

应用程序类中编写此代码

 public Context currentactvity = null;
public Context getCurrentactvity() {
    return currentactvity;
}
public void setCurrentactvity(Context currentactvity) {
    this.currentactvity = currentactvity;
}

在每个活动 Onresume 方法和 Onpause 方法中编写此代码，将

null 写入

 // in onresume
MyApplication.getInstance().setCurrentactvity(this);
// in onpause
MyApplication.getInstance().setCurrentactvity(null);

现在您可以从服务类调用活动方法

  if (MyApplication.getInstance().getCurrentactvity() != null && MyApplication.getInstance().getCurrentactvity() instanceof youractivityname) {
            ((youractivityname) MyApplication.getInstance().getCurrentactvity()).youmethodname(parameter);
        }

Answer 2

如何与服务中的正在运行的活动进行交互，或者实现预期行为的正确方法是什么？

最好的方法是简单地使用事件总线(即GreenRobot或本地广播(。您的活动在onResume()中注册侦听器(并在onPause()中取消注册(，并且您的服务只是在时机成熟时广播消息。

主要好处是您可以将两个元素(服务和活动(完全分开。您还可以避免最糟糕的解决方案 - 直接调用 Activity 的方法。

要了解您是否在后台，最好使用应用程序的GreenRobot的ActivityLifecycleCallbacks - 强迫活动报告这一点是没有意义的，因为完全没有好处。

Answer 3

尝试这样做：

此方法检查所有正在运行的应用，无论当前应用处于后台状态还是前台状态，都返回 true 或 false。

    public static boolean isAppIsInBackground(Context context) {
        boolean isInBackground = true;
        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT_WATCH) {
            List<ActivityManager.RunningAppProcessInfo> runningProcesses = am.getRunningAppProcesses();
            for (ActivityManager.RunningAppProcessInfo processInfo : runningProcesses) {
                if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
                    for (String activeProcess : processInfo.pkgList) {
                        if (activeProcess.equals(context.getPackageName())) {
                            isInBackground = false;
                        }
                    }
                }
            }
        } else {
            List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);
            ComponentName componentInfo = taskInfo.get(0).topActivity;
            if (componentInfo.getPackageName().equals(context.getPackageName())) {
                isInBackground = false;
            }
        }
        return isInBackground;
    }

Answer 4

尝试

1. 在您的活动中注册自定义广播接收器

context.registerReceiver (myBroadcastReceiver, new IntentFilter ("CUSTOM_ACTION"));
private final BroadcastReceiver myBroadcastReceiver = new BroadcastReceiver () {
    @Override
    public void onReceive (Context context, Intent intent) {
        //Do something
    }
};

2. 从您的服务发送广播

Intent intent = new Intent ("CUSTOM_ACTION");
context.sendBroadcast (intent)