无法从 IntentService 中的 LocalBroadcastManager 接收 Activity 中的广播

Question

在Activity和IntentService之间使用广播是非常简单的代码。 MainActivity 启动 SyncService（这是一个 IntentService），SyncService 广播消息，MainActivity 应该从 SyncService 接收消息（通过使用 BroadcastReceiver）。

但奇怪的是 MainActivity 无法从 SyncService 获得任何消息。不知何故，如果我直接在 MainActivity 中调用 LocalBroadcastManager 广播消息（onCreate() 方法），接收者可以得到消息。

是不是因为初始化LocalBroadcastManager的上下文不同？还是有其他问题？

谢谢！

MainActivity 中的相关代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    IntentFilter statusIntentFilter = new IntentFilter(AppConstants.BROADCAST_ACTION);

    LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
            statusIntentFilter);

    final Intent intent = new Intent(this, SyncService.class);
    this.startService(intent);
    this.sendMessage();
}

private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        // Get extra data included in the Intent
        String message = intent.getStringExtra("message");
        Log.d("receiver", "Got message: " + message);
    }
};

SyncService中的相关代码：

public class SyncService extends IntentService {

    private static final String TAG = "SyncService";

    public SyncService() {
        super("SyncService");
        mBroadcaster = new BroadcastNotifier(this);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        Log.d(TAG, "Handle intent");
        mBroadcaster.broadcastIntentWithState(AppConstants.STATE_ACTION_STARTED);

        mBroadcaster.broadcastIntentWithState(AppConstants.STATE_ACTION_COMPLETE);

        Log.d(TAG, "Finish intent");
    }

    private BroadcastNotifier mBroadcaster;
}

BroadcastNotifier 中的相关代码：

private LocalBroadcastManager mBroadcaster;

public BroadcastNotifier(Context context) {

    // Gets an instance of the support library local broadcastmanager
    Log.d(TAG, "Start to create broadcast instance with context: " + context);
    mBroadcaster = LocalBroadcastManager.getInstance(context);

}

public void broadcastIntentWithState(int status) {

   Intent localIntent = new Intent(AppConstants.BROADCAST_ACTION);

   // The Intent contains the custom broadcast action for this app
   //localIntent.setAction();

   // Puts the status into the Intent
   localIntent.putExtra(AppConstants.EXTENDED_DATA_STATUS, status);
   localIntent.addCategory(Intent.CATEGORY_DEFAULT);

   // Broadcasts the Intent
   mBroadcaster.sendBroadcast(localIntent);

}

Answer 1

从broadcastIntentWithState() 中删除addCategory()。这通常不用于任何类型的广播（系统或本地），并且您的 IntentFilter 未按类别过滤。