读取蓝牙数据并放入MainActivity

Question

我一直在寻找这个，但我尝试过的一切都没有奏效。我实施了蓝牙连接服务 class，让我可以通过蓝牙连接并向 HC-05 模块发送消息。我能够在控制台中看到每条消息（带有日志），但是，无论我尝试了什么，我似乎都无法将接收到的字节放入我可以处理的主 activity 中。这是我在我的日志所在的 BluetoothConnectionService class 中的代码：

蓝牙连接服务：

private Handler mHandler; // handler that gets info from Bluetooth service

// Defines several constants used when transmitting messages between the
// service and the UI.
private interface MessageConstants {
    public static final int MESSAGE_READ = 0;
    public static final int MESSAGE_WRITE = 1;
    public static final int MESSAGE_TOAST = 2;

    // ... (Add other message types here as needed.)
}    

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

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

                    // Send the obtained bytes to the MainActivity
                    Handler mainActivityHandler = new Handler();
                    mainActivityHandler.obtainMessage(MessageConstants.MESSAGE_READ, bytes, -1, buffer);

                    // Send the obtained bytes to the UI activity.
                    /*Message readMsg = mHandler.obtainMessage(
                            MessageConstants.MESSAGE_READ, bytes, -1,
                            buffer);
                    readMsg.sendToTarget();*/
                } catch (IOException e) {
                    Log.e(TAG, "write: Error reading Input Stream. " + e.getMessage() );
                    break;
                }
            }
        }

MainActivity:（在onCreate中）

btnReadGlucose.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //On va envoyer quelle personne il faut lire le data
                String patientName = mSpinner.getSelectedItem().toString();
                int patientPosition = mSpinner.getSelectedItemPosition();
                Log.d(TAG, "Le patient " + patientName + " a la position " + patientPosition + " est selectionne");

                //Trouver quelle lettre envoyer
                DataEnvoyer = mappingPatients(patientPosition);
                RequestData = true;

                //Envoi du data
                envoyerCommandeBluetooth(DataEnvoyer);

                //How do I call my handler ?

            }
        });

我仍然是蓝牙通信处理程序的新手。我想我已经接近答案了，但我真的不知道如何在字节中获取消息并将其保存到我的主 activity.

中的值

有人能帮忙吗？

谢谢， luisarcher.

Answer 1

方法 1：如果此服务运行与 activity 在同一线程上，则将服务与 activity 绑定。

//IN YOUR ACTIVITY 
startService(new Intent(getApplicationContext(), BluetoothService.class));
bindService(new Intent(getApplicationContext(), BluetoothService.class), mServiceConnection, Context.BIND_AUTO_CREATE);


private ServiceConnection mServiceConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        BluetoothService.BackgroundBinder backgroundBinder = (BluetoothService.BackgroundBinder) iBinder;
        mBackgroundService = backgroundBinder.getBackgroundService();
        startPinging();
}

    @Override
    public void onServiceDisconnected(ComponentName componentName) {
        mBackgroundService = null;
        }
};

//IN SERVICE
public class BluetoothBinder extends Binder {
    public BluetoothService getBluetoothService() {
        return BluetoothService.this;
    }
}

@Override
public IBinder onBind(Intent intent) {
    Log.d(TAG, "Inside onBind");
    return new BluetoothBinder();
}

现在服务已绑定，您可以在服务中为 incomingMessage 声明一个 getter，这样当您按下 activity 中的按钮时，它 returns 您将收到消息。

方法 2（通过 HANDLER）：如果您需要一个界面来跨进程通信，您可以创建一个 Messenger。它处理单线程上的通信。我还没有这样做，但是可以找到关于此的很好的 post here。

方法 3（通过 LocalBroadCast）：在您的蓝牙服务中，每当您收到消息时发送一个 localBroadcast

//SERVICE
private void sendMessage(String incomingMessage) {
    Intent intent = new Intent("UNIQUE_ACTION");
    intent.putExtra("incomingMessage", incomingMessage);
    LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}

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

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

//ACTIVITY
@Override
public void onResume() {
    super.onResume();
    // This registers mMessageReceiver to receive messages.
    LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,new IntentFilter("UNIQUE_ACTION"));
}

// Handling the received Intents for the "UNIQUE_ACTION" event 
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
    // Extract data included in the Intent
    String incomingMessage = intent.getStringExtra()("incomingMessage");
    Log.d(TAG, incomingMessage);
    }
};

@Override
protected void onPause() {
    // Unregister since the activity is not visible
    LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
    super.onPause();
}

此外，我建议查看此 link 以了解 service and activity.

之间的通信

P.S：看看这个 library for bluetooth communication.It 确实提供了从蓝牙获取数据的方法，我亲自测试过它可以与 HC-05 一起使用，并且有例子。

读取蓝牙数据并放入MainActivity

Reading Bluetooth data and putting it to MainActivity

java

android

bluetooth

handler