java - 如何从广播接收器向主要 Activity 发送消息

Question

我知道这是一个基本问题，这里有很多类似的问题，但是，我浏览了几十个，他们都以特定的方式提出问题，他们的回答并不能解决我的问题。

在我的主要 Activity 类中，我有:

public static class GcmBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
            }
}

当我收到某个 gcm 消息时，我想转换到一个新的屏幕/Activity 。这需要在 mainActivity 的上下文中完成。那么我如何向主要 Activity 发送消息以告诉它执行此操作。我想我应该使用处理程序，但在这种情况下我不知道确切的语法是什么。我从不“创建”广播接收器，所以我不能在其构造函数中传入一些处理程序。 BCR 是通过我的 list 文件的 Intent 过滤器设置的。 gcm 上的 android 教程就是这样设置的，所以我不想动态创建广播接收器(除非它是唯一的方法)。

Answer 1

public class GCMIntentService extends GCMBaseIntentService {

    public static final String PROJECT_ID = "345657565857";
    private static final String TAG = "GCMIntentService";
    ModelNotificationMessage modelNotificationMessage;

    public GCMIntentService() {
        super(PROJECT_ID);
        Log.d(TAG, "GCMIntentService init");
    }

    @Override
    protected void onError(Context ctx, String sError) {
        // TODO Auto-generated method stub
        Log.d(TAG, "Error: " + sError);

    }

    @Override
    protected void onMessage(Context ctx, Intent intent) {

        Log.d(TAG, "Message Received");

        String message = intent.getStringExtra("message");

        Log.d(TAG, "Message Received" + message);



                    sendNotification(message);
            Intent broadcastIntent = new Intent();
            broadcastIntent.setAction("GCM_RECEIVED_ACTION");
            broadcastIntent.putExtra("gcm", message);
            ctx.sendBroadcast(broadcastIntent);

    }

    private void sendNotification(String message) {
        // this
        String ns = Context.NOTIFICATION_SERVICE;
        NotificationManager mNotificationManager = (NotificationManager)                            getSystemService(ns);

        int icon = R.drawable.notification;
        CharSequence tickerText = message; // ticker-text
        long when = System.currentTimeMillis();
        Context context = getApplicationContext();
        CharSequence contentTitle = modelNotificationMessage.getKey();
        CharSequence contentText = message;
        Intent notificationIntent = null;

        int NOTIFICATION_ID = 9999;

                NOTIFICATION_ID = CommonVariable.notification_message;
                notificationIntent = new Intent(this, ViewMessages.class);



        // and this
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
                notificationIntent, 0);
        Notification notification = new Notification(icon, tickerText, when);
        // Play default notification sound
        notification.defaults |= Notification.DEFAULT_ALL;
        notification.setLatestEventInfo(context, contentTitle, contentText,
                contentIntent);
        mNotificationManager.notify(NOTIFICATION_ID, notification);
    }

    @Override
    protected void onRegistered(Context ctx, String regId) {
        // TODO Auto-generated method stub
        // send regId to your server
        Log.d(TAG, regId);

    }

    @Override
    protected void onUnregistered(Context ctx, String regId) {
        // TODO Auto-generated method stub
        // send notification to your server to remove that regId

    }

}

然后广播接收器在您的主 Activity 中调用 onresume 方法。

public void onResume() {

        gcmFilter = new IntentFilter();
        gcmFilter.addAction("GCM_RECEIVED_ACTION");
        viewMessages.registerReceiver(gcmReceiver, gcmFilter);

    }





// A BroadcastReceiver must override the onReceive() event.
    private BroadcastReceiver gcmReceiver = new BroadcastReceiver() {

        private String broadcastMessage;

        @Override
        public void onReceive(Context context, Intent intent) {

            broadcastMessage = intent.getExtras().getString("gcm");

            if (broadcastMessage != null && viewMessages != null) {
                // display our received message
                 onResume();
            }
        }
    };

希望对你有用。