Question

我想将LocalBroadcastManager设置为侦听文本文件和图像文件，并相应地更新适配器。这是我的代码：

// register the receiver to listen for incoming messages
        LocalBroadcastManager.getInstance(getBaseContext())
                .registerReceiver(new BroadcastReceiver() {
                    @Override
                    public void onReceive(Context context, Intent intent) {
//Receive text messages
                        Message message = new Message(intent.getStringExtra(ChatFragment.INTENT_EXTRA_MSG));
                        message.setDeviceName(intent.getStringExtra(ChatFragment.INTENT_EXTRA_NAME));
                        message.setDirection(Message.INCOMING_MESSAGE);
                        adapter.addMessage(message);

                        //Log.i(TAG, "onReceive: received message to adapter");

//Receive image files
                        com.bridgefy.sdk.client.Message fmessage = intent.getParcelableExtra(FileFragment.INTENT_EXTRA_MSG);
                        byte[] fileBytes = fmessage.getData();
                        BridgefyFile bridgefyFile = new BridgefyFile((String)fmessage.getContent().get("file"));
                        bridgefyFile.setData(fileBytes);
                        bridgefyFile.setDeviceName(intent.getStringExtra(FileFragment.INTENT_EXTRA_NAME));
                        bridgefyFile.setDirection(BridgefyFile.INCOMING_FILE);
                        adapter.addFile(bridgefyFile);
                    }
                }, new IntentFilter(conversationId));

收到消息后，应用程序崩溃并显示错误：

java.lang.NullPointerException: Attempt to invoke virtual method 'byte[] com.bridgefy.sdk.client.Message.getData()' on a null object reference

我怀疑原因是因为BroadcastManager也正在以相同的意图监听图像

Answer 1

收听文本文件和图像文件并更新适配器相应地

您可以为此使用Actions

private BroadcastReceiver mBluetoothReceiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            switch (action) {
                case "Action1":
                    break;
                case "Action2":
                    break;
            }
        }
    };

然后，当您发送广播时，只需根据自己的意图设置操作

intent.setAction("Action1")

如何将LocalBroadcastManager设置为侦听两种数据类型

1 个答案: