Question

在Activity和IntentService之间使用广播是非常简单的代码。 MainActivity启动SyncService（它是一个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获取任何消息。不知怎的，如果我调用LocalBroadcastManager直接在MainActivity（onCreate（）方法）中广播消息，接收者就可以得到消息。

是不是因为初始化LocalBroadcastManager的上下文不同？或者还有其他问题吗？

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addCategory()移除broadcastIntentWithState()。这通常不适用于任何类型的广播（系统或本地），而您的IntentFilter不会过滤类别。

无法从IntentService中的LocalBroadcastManager接收Activity中的广播

1 个答案: