Einen Char über Bluetooth senden

[Martin2013]

Habe ein Bluetooth Tutorial durchgemacht, wo das Grundgerüst für eine Bluetooth App gebaut wird.

Meine App im moment :

package com.example.bluetooth;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.WriteAbortedException;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.text.DynamicLayout;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

public class MainActivity extends Activity implements OnItemClickListener {


    ArrayAdapter<String> listAdapter;
    public Button connectNew;
    public ListView listView;
    BluetoothAdapter btAdapter;
    Set<BluetoothDevice> devicesArray;
    ArrayList<String> pairedDevices;
    ArrayList<BluetoothDevice> devices;
    private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
    private static final int SUCCESS_CONNECT = 0;
    private static final int MESSAGE_READ = 1;
    IntentFilter filter;
    BroadcastReceiver receiver;
    Handler mHandler = new Handler(){
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch(msg.what){
            case SUCCESS_CONNECT:
                ConnectedThread connectedThread = new ConnectedThread((BluetoothSocket)msg.obj);
                
                Toast.makeText(getApplicationContext(), "CONNECT", 0).show();
                String s = "successfully connected";
                connectedThread.write(s.getBytes());
                
                break;
            
            case MESSAGE_READ:
                byte[] readBuf = (byte[])msg.obj;
                String string = new String(readBuf);
                Toast.makeText(getApplicationContext(), "CONNECT", 0).show();
                
                break;
            }
            
            
        }
    };

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        if(btAdapter ==null){
            Toast.makeText(getApplicationContext(), "No Bluetooth detected", 0).show();
            finish();
            
        }else{
            if(!btAdapter.isEnabled()){
                turnOnBT();
            }
        }
        getPairedDevices();
        startDiscovery();
        
                
            }
    

    
    private void startDiscovery() {
        btAdapter.cancelDiscovery();
        btAdapter.startDiscovery();
        
        
    }


    private void turnOnBT() {
        Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(intent, 1);
        
    }


    private void getPairedDevices() {
        devicesArray = btAdapter.getBondedDevices();
        if(devicesArray.size()<0){
            for(BluetoothDevice device:devicesArray){
                pairedDevices.add(device.getName());
            }
        }
    }


    private void init() {
        connectNew=(Button)findViewById(R.id.bConnectNew);
        listView=(ListView)findViewById(R.id.listView1);
        listView.setOnItemClickListener(this);
        listAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,0);
        listView.setAdapter(listAdapter);
        btAdapter = BluetoothAdapter.getDefaultAdapter();
        pairedDevices = new ArrayList<String>();
        devices = new ArrayList<BluetoothDevice>();
        filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        receiver = new BroadcastReceiver() {
        
            @Override
            public void onReceive(Context context, Intent intent) {
                // TODO Auto-generated method stub
                String action = intent.getAction();
                
                if(BluetoothDevice.ACTION_FOUND.equals(action)){
                    BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                    devices.add(device);
                    String s = "";
                    for(int a = 0; a < pairedDevices.size(); a++){
                        if(device.getName().equals(pairedDevices.get(a))){
                            //append
                            
                            s = "PAIRED";
                            break;
                        }
                    }
                    listAdapter.add(device.getName()+ " (" + s + ") "+"\n"+device.getAddress());
                    
                }else if(BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)){
                    //run some code
                }else if(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
                    if(listAdapter.getCount()>0){
                        for(int i = 0; i < listAdapter.getCount(); i++){
                            
                        }
                    }

                }else if(BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)){
                    if(btAdapter.getState()==btAdapter.STATE_OFF){
                        turnOnBT();
                    }
                    
                }
            }
        };
        registerReceiver(receiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
        registerReceiver(receiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        registerReceiver(receiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
        registerReceiver(receiver, filter);
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        unregisterReceiver(receiver);
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);
        if(resultCode == RESULT_CANCELED){
            Toast.makeText(getApplicationContext(), "Bluetooth must be enabled to continue", Toast.LENGTH_SHORT).show();
            finish();
        }
    }

    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }


    @Override
    public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
        // TODO Auto-generated method stub
        
        if(btAdapter.isDiscovering()){
            btAdapter.cancelDiscovery();
        }
        if(listAdapter.getItem(arg2).contains("PAIRED")){
        
        BluetoothDevice selectedDevice = devices.get(arg2);
        ConnectThread connect = new ConnectThread(selectedDevice);
        connect.start();
        
        
    }else{
        Toast.makeText(getApplicationContext(), "Device is paired", 0).show();
    }
    }
        private class ConnectThread extends Thread {
            
            private final BluetoothSocket mmSocket;
            private final BluetoothDevice mmDevice;
         
            public ConnectThread(BluetoothDevice device) {
                // Use a temporary object that is later assigned to mmSocket,
                // because mmSocket is final
                BluetoothSocket tmp = null;
                mmDevice = device;
         
                // Get a BluetoothSocket to connect with the given BluetoothDevice
                try {
                    // MY_UUID is the app's UUID string, also used by the server code
                    tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
                } catch (IOException e) { }
                mmSocket = tmp;
            }
         
            public void run() {
                // Cancel discovery because it will slow down the connection
                btAdapter.cancelDiscovery();
         
                try {
                    // Connect the device through the socket. This will block
                    // until it succeeds or throws an exception
                    mmSocket.connect();
                } catch (IOException connectException) {
                    // Unable to connect; close the socket and get out
                    try {
                        mmSocket.close();
                    } catch (IOException closeException) { }
                    return;
                }
         
                // Do work to manage the connection (in a separate thread)
    
                mHandler.obtainMessage(SUCCESS_CONNECT, mmSocket).sendToTarget();
            }
         


            /** Will cancel an in-progress connection, and close the socket */
            public void cancel() {
                try {
                    mmSocket.close();
                } catch (IOException e) { }
            }
        }
        
        private class ConnectedThread extends Thread {
            private final BluetoothSocket mmSocket;
            private final InputStream mmInStream;
            private final OutputStream mmOutStream;
         
            public ConnectedThread(BluetoothSocket socket) {
                mmSocket = socket;
                InputStream tmpIn = null;
                OutputStream tmpOut = null;
         
                // Get the input and output streams, using temp objects because
                // member streams are final
                try {
                    tmpIn = socket.getInputStream();
                    tmpOut = socket.getOutputStream();
                } catch (IOException e) { }
         
                mmInStream = tmpIn;
                mmOutStream = tmpOut;
            }
         
            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) {
                    try {
                        // Read from the InputStream
                        bytes = mmInStream.read(buffer);
                        // Send the obtained bytes to the UI activity
                        mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
                                .sendToTarget();
                    } catch (IOException e) {
                        break;
                    }
                }
            }
         
            /* Call this from the main activity to send data to the remote device */
            public void write(byte[] bytes) {
                try {
                    mmOutStream.write(bytes);
                } catch (IOException e) { }
            }
         
            /* Call this from the main activity to shutdown the connection */
            public void cancel() {
                try {
                    mmSocket.close();
                } catch (IOException e) { }
            }
        }
}

Jetz will ich einen Button haben, der wenn ich draufklicke einfach z.B. 'a' rausschreiben soll. Aber wie mach ich das ? Ich schreib einen onClickListener für meinen Button, aber wie schreib ich jetz einen char hinaus.

Hab nur was von write.byte gelesen aber das versteh ich nicht so ganz.

Hoffe auf ein paar Tipps!