当广播接收器收到消息时，更新 recyclerview 的切换按钮

Question

我正在开发接收蓝牙数据的应用程序。该应用程序包含一个 activity 和一些片段，一个片段有一个带有一些项目的回收视图，每个项目都有一个切换按钮、一个文本视图和一个图像视图。我想在广播接收器收到消息时设置检查特定的切换按钮。例如，如果传入消息包含“1”，则位置 1 的切换按钮应该打开。

BluetoothConnectionSericve.java:

/**
     *Finally the ConnectedThread which is responsible for maintaining
     * the BTConnection, Sending the data,and receiving incoming data
     * through input/output streams respectively.
     */
    private class ConnectedThread extends Thread{
        private final BluetoothSocket bluetoothSocket;
        private final InputStream inputStream;
        private final OutputStream outputStream;

        public ConnectedThread(BluetoothSocket socket){
            Log.d(TAG,"ConnectedThread: Starting.");
            bluetoothSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            //Dismiss the progressDialog when connection is established
            progressDialog.dismiss();

            try {
                tmpIn = bluetoothSocket.getInputStream();
                tmpOut = bluetoothSocket.getOutputStream();
            } catch (IOException e) {
                e.printStackTrace();
            }

            inputStream = tmpIn;
            outputStream = tmpOut;
        }

        public void run(){
            byte[] buffer = new byte[1024]; //buffer store the stream
            int bytes; //bytes returned from read()

            //Keep listening to the inputStream until an exception is occurs
            while (true){
                //Read from the input stream
                try {
                    bytes = inputStream.read(buffer);
                    String inComingMessage = new String(buffer, 0, bytes);
                    Log.d(TAG,"InputStream: " + inComingMessage);

                    Intent incomingMessageIntent = new Intent("incomingMessage");
                    incomingMessageIntent.putExtra("receivedMessage", inComingMessage);
                    LocalBroadcastManager.getInstance(context).sendBroadcast(incomingMessageIntent);

                } catch (IOException e) {
                    Log.d(TAG, "write: Error listening to inputStream: " + e.getMessage());
                    break;
                }
            }
        }

广播接收器：

LocalBroadcastManager.getInstance(context).registerReceiver(receiver, new IntentFilter("incomingMessage"));

    BroadcastReceiver receiver = new BroadcastReceiver() {
                    @Override
                    public void onReceive(Context context, Intent intent) {

                            // new push notification is received
                            msg = intent.getStringExtra("receivedMessage");
                            if (msg.equals("1")){
                                //Set the toggle button at position 1 to true
                            }

                    }
                }

Answer 1

创建一个方法来设置适配器中的数据class。我将使用 class Item 的通用 ArrayList 作为示例。

class Item{

private boolean toggleOn;

Item(boolean toggleOn){ this.toggleOn = toggleOn; }

getToggleOn(){ return toggleOn };

setToggleOn(boolean toggleOn) { this.toggleOn = toggleOn }

}

在您的适配器中，您应该有一个 Item 对象的 ArrayList 和一个设置数据的方法。我假设您知道如何使用 RecyclerView 适配器，所以我不考虑视图持有者。

class ItemAdapter extends RecyclerView.Adapter{

ArrayList<Item> items;

ItemAdapter(ArrayList<Item> items) { this.items = items }

@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.custom_row, parent, false);
    return new MyViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
    holder.toggleButton.setChecked(items.get(position).getToggleOn());
}

@Override
public int getItemCount() {
    return items.size();
}

void toggleItemOn(int position){
items.get(position).setToggleOn(true);
notifyDataSetChanged();
}

}

然后在你的 BroadcastReceiver onReceive()

BroadcastReceiver receiver = new BroadcastReceiver() {

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

        // new push notification is received
        msg = intent.getStringExtra("receivedMessage");
        //Set the toggle button at given position to true
        //Integer.valueOf() converts a string to an Integer value
        //You may need to catch an exception if it cannot be converted
        //You will want to make sure msg does not give a higher value than your item array size.
        adapter.toggleItemOn(Integer.valueOf(msg));
    }
}

当广播接收器收到消息时，更新 recyclerview 的切换按钮

Update the toggle button at recyclerview when the broadcast receiver gets the message

java

android

bluetooth

broadcastreceiver