Activity与GCMListenerService Android的通信

Question

我正在使用GCM开发一个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，它扩展了GCMListenerService。在onMessageReceived(String from, Bundle data)中，我能够在推送通知中获得消息。

现在，每当在推送中收到特定消息时，我希望访问我的MainActivity类中的一个方法。

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();

    }
}

每当收到消息“BEGINTask”时，我希望beginTask()方法执行。

我知道一种方法是通过服务->接口->活动架构，但是我不能使用它，因为我从来没有创建过PushNotificationService.的对象。

请帮帮忙。

更新：-我现在使用的是库，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");


    }
}

问题仍未得到解决，问题仍未得到解决。beginTask()在MainActivity.java中仍然没有被调用。

Answer 1

使用eventBus库来促进这个过程..。

我在这个过程中使用了Otto，http://square.github.io/otto/

下面是另一个eventBus库https://greenrobot.github.io/EventBus/

步骤：

1.从服务中创建事件

2.在活动中添加侦听器

3.如果活动正在运行，则将执行该方法。

**编辑1：*

我把奥托巴士抽象成这样。

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并尝试发布事件

为Jcarlo的评论编辑2

按照以下步骤查找活动的状态。

1. 在您的活动的onResume调用MyBus.getInstance().register(this)中。
2. 在您的活动的onPause调用MyBus.getInstance().unregister(this)中。
3. 在发布消息之前，在GCM IntentService中 如果(MyBus.getInstance().isRegistered()){ //app是活着的//post数据}，则{//显示通知}

希望这能有所帮助

Answer 2

您可以使用LocalBroadcastManager。在您的LocalBroadcastManager的onCreate上创建一个onCreate对象mBroadcaster = LocalBroadcastManager.getInstance(this);，并使用

@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，您可以在MainActivity中使用BroadcastReceiver接收消息。

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

此外，您还需要在活动的onStart和onStop中注册和取消接收方。

@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);
}