Activity与GCMListenerService Android之间的通信

Question

我正在使用GCM开发具有推送通知功能的android应用程序。 我创建了一个名为PushNotificationService的类，该类扩展了GCMListenerService。 在onMessageReceived(String from, Bundle data)我能够在推送通知中获取消息。

现在，无论何时在推送中收到特定消息时，我都想访问MainActivity类中的方法。

以下是我的代码：-

PushNotificationService.java

public class PushNotificationService extends GcmListenerService {

@Override
    public void onMessageReceived(String from, Bundle data) {
        // TODO Auto-generated method stub
        super.onMessageReceived(from, data);



         String message = data.getString("message");

         if(message.equalsIgnoreCase("Begin Task"))
            {

                    //call method from MainActivity.class

            }

        }
}

MainActivty.java

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }

    public void beginTask()

    {

        Log.d("GCM","Message Received from Server");
        finish();

    }
}

我希望每当收到消息“ Begin Task”时都执行beginTask（）方法。

我知道一种方法是通过Service-> Interface-> Activity体系结构，但是我无法使用它，因为我从未创建过PushNotificationService的对象。

请帮忙。

更新：-我现在正在使用Otto库，下面是我的代码。

添加了新的MyBus.java

public class MyBus extends Bus {
    private static Bus bus;
    //isRegistered is used to track the current registration status
    private static boolean isRegistered;
    private Handler handler = new Handler(Looper.getMainLooper());

    public MyBus() {
        if (bus == null) {
            //ANY will allow event bus to run even with services
            //and broadcast receivers
            bus = new Bus(ThreadEnforcer.ANY);
        }
    }

    @Override
    public void register(Object obj) {
        //The bus is registered when an activity starts
        bus.register(obj);
        isRegistered = true;
    }

    @Override
    public void unregister(Object obj) {
        //The bus is unregistered when an activity goes to background
        bus.unregister(obj);
        isRegistered = false;
    }

    @Override
    public void post(final Object event) {
        if (Looper.myLooper() == Looper.getMainLooper()) {
            //post the event in main thread or background thread
            bus.post(event);
        } else {
            handler.post(new Runnable() {
                @Override
                public void run() {
                    bus.post(event);
                }
            });
        }
    }

    public boolean isRegistered(){
        return isRegistered;
    }
}

PushNotificationService.java

public class PushNotificationService extends GcmListenerService {

@Override
    public void onMessageReceived(String from, Bundle data) {
        // TODO Auto-generated method stub
        super.onMessageReceived(from, data);

        MyBus myBus = new MyBus();
        myBus.register(myBus);

         String message = data.getString("message");

         if(message.equalsIgnoreCase("Begin Task"))
            {

                    myBus.post(message);

            }

        }
}

MainActivity.java

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }

    @Subscribe
    public void beginTask()

    {

        Log.d("GCM","Message Received from Server");


    }
}

问题仍然没有解决 。 MainActivity.java中的beginTask（）仍未调用。

Answer 1

使用eventBus库促进此过程...

我将Otto用于此过程http://square.github.io/otto/
这是另一个eventBus库https://greenrobot.github.io/EventBus/

脚步：
1.从服务创建事件
2.在活动中添加一个侦听器
3.如果活动正在运行，该方法将被执行

**编辑1：**
我已经像这样抽象了otto总线。

package com.mypackage.eventBus;

import android.os.Handler;
import android.os.Looper;

import com.squareup.otto.Bus;
import com.squareup.otto.ThreadEnforcer;

/**
 * Created by gowtham on 10/6/15.
 */
public class MyBus extends Bus {
    private static Bus bus;
    //isRegistered is used to track the current registration status
    private static boolean isRegistered;
    private Handler handler = new Handler(Looper.getMainLooper());

    public MyBus() {
        if (bus == null) {
            //ANY will allow event bus to run even with services
            //and broadcast receivers
            bus = new Bus(ThreadEnforcer.ANY);
        }
    }

    @Override
    public void register(Object obj) {
        //The bus is registered when an activity starts
        bus.register(obj);
        isRegistered = true;
    }

    @Override
    public void unregister(Object obj) {
        //The bus is unregistered when an activity goes to background
        bus.unregister(obj);
        isRegistered = false;
    }

    @Override
    public void post(final Object event) {
        if (Looper.myLooper() == Looper.getMainLooper()) {
            //post the event in main thread or background thread
            bus.post(event);
        } else {
            handler.post(new Runnable() {
                @Override
                public void run() {
                    bus.post(event);
                }
            });
        }
    }

    public boolean isRegistered(){
        return isRegistered;
    }
}

创建上述对象的实例，然后尝试发布事件

编辑2对Jcarlo的评论
请按照以下步骤查找活动的状态。

1. 在活动的onResume中，调用MyBus.getInstance（）。register（this）。
2. 在活动的onPause中，调用MyBus.getInstance（）。unregister（this）。

3. 在发布消息之前，在您的GCM IntentService中

   if（MyBus.getInstance（）。isRegistered（））{//应用程序处于活动状态//发布数据} else {//显示通知}

希望这可以帮助

Answer 2

您可以使用LocalBroadcastManager 。 创建一个LocalBroadcastManager对象mBroadcaster = LocalBroadcastManager.getInstance(this); 在您的GCMListener的onCreate上发送

@Override
public void onCreate() {
    super.onCreate();
    mBroadcaster = LocalBroadcastManager.getInstance(this);
}

@Override
public void onMessageReceived(String from, Bundle data) {
    super.onMessageReceived(from, data);

     String message = data.getString("message");

     if(message.equalsIgnoreCase("Begin Task")) {
        Intent i = new Intent();
        i.setAction("yourPackageName");
        i.putExtra("DATA", yourData);
        mBroadcaster.send(i);
    }
}

然后，您可以使用BroadcastReceiver在MainActivity接收消息。

BroadCastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            beginTask();
        }
};

另外，您还需要在活动的onStart和onStop中注册和注销接收者

@Override
protected void onStart() {
    super.onStart();
    IntentFilter filter = new IntentFilter();

    filter.addAction("yourPackageName);
    LocalBroadcastManager.getInstance(this).registerReceiver((mBroadcastReceiver), filter);
}

@Override
protected void onStop() {
    super.onStop();
    LocalBroadcastManager.getInstance(this).unregisterReceiver(mBroadcastReceiver);
}