Android蓝牙通信开发实例演示

时间：12-02来源：作者：点击数：100

在上一节《Android蓝牙（Bluetooth）连接与通讯》教程中我们已经了解如何探测并开启手机的蓝牙功能、蓝牙服务搜索和建立蓝牙连接。下面我们编写实例 BluetoothDemo。实例 BluetoothDemo 演示了使用蓝牙功能对其他蓝牙设备进行搜寻、连接并进行数据传输的过程。该应用程序的运行效果如图 1 所示。

实例BluetoothDemo的运行效果
图 1 实例 BluetoothDemo 的运行效果

该视图整体使用 LinearLayout 布局，使用 ListView 显示聊天内容，下方的横向 LinearLayout 布局中放置了一个用于输入文本的 EditText 和一个按钮。对应的布局文件 main.xml 的内容如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:myapp="http://schemas.android.com/apk/res/android.BluetoothChat"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:background="@drawable/bg01">
   <ListView
      android:id="@+id/in"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:stackFromBottom="true"
      android:transcriptMode="alwaysScroll"
      android:layout_weight="1"/>
   <LinearLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_parent"
      android:orientation="horizontal" >
      <EditText
         android:id="@+id/edit_text_out"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_weight="1"
         android:layout_gravity="bottom"/>
      <ListView
         android:id="@+id/button_send"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@string/send" />
   </LinearLayout>
</LinearLayout>

实例 BluetoothDemo 的 AndroidManifest.xml 文件的内容如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="introduction.android.BluetoothChat"
    android:versionCode="1"
    android:versionName="1.0">
    <uses-sdk android:minSdkVersion="14" />
    <uses-permission android:name="android.permission.BLUE TOOTH_ADMIN">
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <application
        android:icon="@drawable/app_icon"
        android:label="@string/app_name">
        <activity
            android:name=".BluetoothChat"
            android:configChanges="orientation\keyboardHidden"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.in tent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".DeviceList"
            android:configChanges="orientation\keyboardHidden"
            android:label="@string/select_device"
            android:theme="@android:style/Theme.Dialog" />
    </application>
</manifest>

实例 BluetoothDemo 的主 Activity 为 BluetoothChat，其对应的文件内容如下：

package introduction.android.mydbdemo;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.inputmethod.EditorInfo;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class BluetoothChat extends Activity {
    public static final int MESSAGE_STATE_CHANGE = 1;
    public static final int MESSAGE_READ = 2;
    public static final int MESSAGE_WRITE = 3;
    public static final int MESSAGE_DEVICE_NAME = 4;
    public static final int MESSAGE_TOAST = 5;
    public static final String DEVICE_NAME = "device_name";
    public static final String TOAST = "toast";
    private static final int REQUEST_C0NNECT_DEVICE = 1;
    private static final int REQUEST_ENABLE_BT = 2;
    private TextView mTitle;
    private ListView mConversationView;
    private EditText mOutEditText;
    private Button mSendButton;
    private String mConnectedDeviceName = null;
    private ArrayAdapter<String> mConversationArrayAdapter;
    private StringBuffer mOutStringBuffer;
    private BluetoothAdapter mBluetoothAdapter = null;
    private ChatService mChatService = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //设置窗口布局为自定义标题
        requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
        setContentView(R.layout.main);
        //设置窗口标题为布局文件
        getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title);
        mTitle = (TextView) findViewById(R.id.title_left_text);
        mTitle.setText(R.string.app_name);
        mTitle = (TextView) findViewById(R.id.title_right_text);
        // 得到本地蓝牙适配器
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        //若当前设备不支持蓝牙功能
        if (mBluetoothAdapter == null) {
            Toast.makeText(this, "蓝牙不可用", Toast.LENGTH_LONG).show();
            finish();
            return;
        }
    }
    @Override
    public void onStart() {
        super.onStart();
        if (!mBluetoothAdapter.isEnabled()) {
            Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
        } else {
            if (mChatService == null)
                setupChat();
        }
    }
    @Override
    public synchronized void onResume() {
        super.onResume();
        if (mChatService != null) {
            if (mChatService.getState() == ChatService.STATE_NONE) {
                mChatService.start();
            }
        }
    }
    private void setupChat() {
        mConversationArrayAdapter = new ArrayAdapter<String>(this, R.layout.message);
        mConversationView = (ListView) findViewById(R.id.in);
        mConversationView.setAdapter(mConversationArrayAdapter);
        mOutEditText = (EditText) findViewById(R.id.edit_text_out);
        mOutEditText.setOnEditorActionListener(mWriteListener);
        mSendButton = (Button) findViewById(R.id.button_send);
        mSendButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                TextView view = (TextView) findViewById(R.id.edit_text_out);
                String message = view.getText().toString();
                sendMessage(message);
            }
        });
        mChatService = new ChatService(this, mHandler);
        mOutStringBuffer = new StringBuffer("");
    }
    @Override
    public synchronized void onPause() {
        super.onPause();
    }
    @Override
    public void onStop() {
        super.onStop();
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mChatService != null)
            mChatService.stop();
    }
    private void ensureDiscoverable() {
        if (mBluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
            Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
            discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
            startActivity(discoverableIntent);
        }
    }
    private void sendMessage(String message) {
        if (mChatService.getState() != ChatService.STATE_CONNECTED) {
            Toast.makeText(this, R.string.not_connected, Toast.LENGTH_SHORT).show();
            return;
        }
        if (message.length() > 0) {
            byte[] send = message.getBytes();
            mChatService.write(send);
            mOutStringBuffer.setLength(0);
            mOutEditText.setText(mOutStringBuffer);
        }
    }
    private TextView.OnEditorActionListener mWriteListener = new TextView.OnEditorActionListener() {
        public boolean onEditorAction(TextView view, int actionId, KeyEvent event) {
            if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_UP) {
                String message = view.getText().toString();
                sendMessage(message);
            }
            return true;
        }
    };
    private final Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MESSAGE_STATE_CHANGE:
                    switch (msg.argl) {
                        case ChatService.STATE_CONNECTED:
                            mTitle.setText(R.string.title_connected_to);
                            mTitle.append(mConnectedDeviceName);
                            mConversationArrayAdapter.clear();
                            break;
                        case ChatService.STATE_CONNECTING:
                            mTitle.setText(R.string.title_connecting);
                            break;
                        case ChatService.STATE_LISTEN:
                        case ChatService.STATE_NONE:
                            mTitle.setText(R.string.title_not_connected);
                            break;
                    }
                    break;
                case MESSAGE_WRITE:
                    byte[] writeBuf = (byte[]) msg.obj;
                    String writeMessage = new String(writeBuf);
                    mConversationArrayAdapter.add("我: " + writeMessage);
                    break;
                case MESSAGE_READ:
                    byte[] readBuf = (byte[]) msg.obj;
                    String readMessage = new String(readBuf, 0, msg.argl);
                    mConversationArrayAdapter.add(mConnectedDeviceName + ":" + readMessage);
                    break;
                case MESSAGE_DEVICE_NAME:
                    mConnectedDeviceName = msg.getData().getString(DEVICE_NAME);
                    Toast.makeText(getApplicationContext(), "链接到" + mConnectedDeviceName, Toast.LENGTH_SHORT).show();
                    break;
                case MESSAGE_TOAST:
                    Toast.makeText(getApplicationContext(), msg.getData().getString(TOAST), Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    };
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
            case REQUEST_CONNECT_DEVICE:
                if (resultCode == Activity.RESULT_OK) {
                    String address = data.getExtras().getString(DeviceList.EXTRA_DEVICE_ADDRESS);
                    BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
                    mChatService.connect(device);
                }
                break;
            case REQUEST_ENABLE_BT:
                if (resultCode == Activity.RESULT_OK) {
                    setupChat();
                } else {
                    Toast.makeText(this, R.string.bt_not_enabled_leaving,
                            Toast.LENGTH_SHORT).show();
                    finish();
                }
        }
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.option_menu, menu);
        return true;
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.scan:
                Intent serverIntent = new Intent(this, DeviceList.class);
                startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE);
                return true;
            case R.id.discoverable:
                ensureDiscoverable();
                return true;
            case R.id.back:
                finish();
                System.exit(0);
                return true;
        }
        return false;
    }
}

Activity BluetoothChat 的 onCreate() 方法检查当前设备是否支持蓝牙功能，并得到本地的 BluetoothAdapter 设备。

在 onStart() 中检查是否启用了蓝牙功能，若未启用，则请求启用，然后通过 setupChat() 方法对界面中的控件进行初始化、增加单击监听器等，BluetoothChat 创建了 ChatService 对象，该对象在整个应用过程中存在，并完成了蓝牙连接的建立、消息发送与接收等功能。

ChatService.java 的代码如下：

package introduction.android.BluetoothChat;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import introduction.android.mydbdemo.BluetoothChat;
public class ChatService {
    private static final String NAME = "BluetoothChat";
    // UUID-->通用唯一识别码，能唯一辨识资讯
    private static final UUID MY_UUID = UUID
            .fromString("fa87c0d0-afac-llde-8a39-0800200c9a66");
    private final BluetoothAdapter mAdapter;
    private final Handler mHandler;
    private AcceptThread mAcceptThread;
    private ConnectThread mConnectThread;
    private ConnectedThread mConnectedThread;
    private int mState;
    public static final int STATE_NONE = 0;
    public static final int STATE_LISTEN = 1;
    public static final int STATE_CONNECTING = 2;
    public static final int STATE_CONNECTED = 3;
    public ChatService(Context context, Handler handler) {
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = STATE_NONE;
        mHandler = handler;
    }
    private synchronized void setState(int state) {
        mState = state;
        mHandler.obtainMessage(BluetoothChat.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
    }
    public synchronized int getState() {
        return mState;
    }
    public synchronized void start() {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }
        if (mAcceptThread == null) {
            mAcceptThread = new AcceptThread();
            mAcceptThread.start();
        }
        setState(STATE_LISTEN);
    }
    //取消CONNECTING和CONNECTED状态下的相关线程，然后运行新的mConnectThread线程
    public synchronized void connect(BluetoothDevice device) {
        if (mState == STATE_CONNECTING) {
            if (mConnectThread != null) {
                mConnectThread.cancel();
                mConnectThread = null;
            }
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }
        mConnectThread = new ConnectThread(device);
        mConnectThread.start();
        setState(STATE_CONNECTING);
    }
    //开启一个ConnectedThread来管理对应的当前连接。之前先取消任意现存的mConnectThread、
    //mConnectedThread 、mAcceptThread 线程，然后开启新 mConnectedThread ，传入当前刚刚接受的
    //socket连接
    //最后通过Handler来通知UI连接
    public synchronized void connected(BluetoothSocket socket,
                                       BluetoothDevice device) {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }
        if (mAcceptThread != null) {
            mAcceptThread.cancel();
            mAcceptThread = null;
        }
        mConnectedThread = new ConnectedThread(socket);
        mConnectedThread.start();
        Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();
        bundle.putString(BluetoothChat.DEVICE_NAME, device.getName());
        msg.setData(bundle);
        mHandler.sendMessage(msg);
        setState(STATE_CONNECTED);
    }
    //停止所有相关线程，设当前状态为NONE
    public synchronized void stop() {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }
        if (mAcceptThread != null) {
            mAcceptThread.cancel();
            setState(STATE_NONE);
        }
    }
    //在 STATE_CONNECTED 状态下，调用 mConnectedThread 里的 write 方法，写入 byte
    public void write(byte[] out) {
        ConnectedThread r;
        synchronized (this) {
            if (mState != STATE_CONNECTED)
                return;
            r = mConnectedThread;
        }
        r.write(out);
    }
    //连接失败的时候处理，通知ui ,并设为STATE一LISTEN状态
    private void connectionFailed() {
        setState(STATE_LISTEN);
        Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(BluetoothChat.TOAST, "链接不到设备");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }
    //当连接失去的时候，设为STATE_LISTEN状态并通知UI
    private void connectionLost() {
        setState(STATE_LISTEN);
        Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(BluetoothChat.TOAST, "设备链接中断");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }
    //创建监听线程，准备接受新连接。使用阻塞方式调用BluetoothServerSocket.accept()
    private class AcceptThread extends Thread {
        private final BluetoothServerSocket mmServerSocket;
        public AcceptThread() {
            BluetoothServerSocket tmp = null;
            try {
                tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
            } catch (IOException e) {
            }
            mmServerSocket = tmp;
        }
        public void run() {
            setName("AcceptThread");
            BluetoothSocket socket = null;
            while (mState != STATE_CONNECTED) {
                try {
                    socket = mmServerSocket.accept();
                } catch (IOException e) {
                    break;
                }
                if (socket != null) {
                    synchronized (ChatService.this) {
                        switch (mState) {
                            case STATE_LISTEN:
                            case STATE_CONNECTING:
                                connected(socket, socket.getRemoteDevice());
                                break;
                            case STATE_NONE:
                            case STATE_CONNECTED:
                                try {
                                    socket.close();
                                } catch (IOException e) {
                                }
                                break;
                        }
                    }
                }
            }
        }
        public void cancel() {
            try {
                mmServerSocket.close();
            } catch (IOException e) {
            }
        }
    }
    // 连接进程，专门用来对外发出连接对方蓝牙的请求并进行处理
    // 构造函数里，通过BluetoothDevice.createRfcommSocketToServiceRecord(),
    // 从待连接的device产生BluetoothSocket.然后在run方法中connect ,
    // 成功后调用BluetoothChatSevice的connected() 方法。定义cancel()再关闭线程时能关闭相关Socket
    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;
        public ConnectThread(BluetoothDevice device) {
            mmDevice = device;
            BluetoothSocket tmp = null;
            try {
                tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
            } catch (IOException e) {
            }
            mmSocket = tmp;
        }
        public void run() {
            setName("ConnectThread");
            mAdapter.cancelDiscovery();
            try {
                mmSocket.connect();
            } catch (IOException e) {
                connectionFailed();
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                }
                ChatService.this.start();
                return;
                synchronized (ChatService.this) {
                    mConnectThread = null;
                }
                connected(mmSocket, mmDevice);
            }
        }
        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
            }
        }
    }
    // 双方蓝牙连接后一直运行的线程。构造函数中设置输入输出流
    // Run方法中使用阻塞模式的Inputstream.read()循环读取输入流，
    // 然后post到UI线程中更新聊天信息。也提供了write()将聊天信息写入输出流传输至对方，传输成功后回写入UI线程，最后cancle()关闭连接的socket
    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;
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
            }
            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }
        public void run() {
            byte[] buffer = new byte[1024];
            int bytes;
            while (true) {
                try {
                    bytes = mmInStream.read(buffer);
                    mHandler.obtainMessage(BluetoothChat.MESSAGE_READ, bytes,
                            -1, buffer).sendToTarget();
                } catch (IOException e) {
                    connectionLost();
                    break;
                }
            }
        }
        public void write(byte[] buffer) {
            try {
                mmOutStream.write(buffer);
                mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer).sendToTarget();
            } catch (IOException e) {
            }
        }
    }
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) {
        }
    }
}

DeviceList 用于显示蓝牙设备列表，并返回蓝牙设备信息。DeviceList.java 的代码如下：

package introduction.android.BluetoothChat;
import java.util.Set;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
import introduction.android.mydbdemo.R;
public class DeviceList extends Activity {
    public static String EXTRA_DEVICE_ADDRESS = "device_address";
    private BluetoothAdapter mBtAdapter;
    private ArrayAdapter<String> mPairedDevicesArrayAdapter;
    private ArrayAdapter<String> mNewDevicesArrayAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setContentView(R.layout.device_list);
        setResult(Activity.RESULT_CANCELED);
        Button scanButton = (Button) findViewById(R.id.button_scan);
        scanButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                doDiscovery();
                v.setVisibility(View.GONE);
            }
        });
        mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
        mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
        ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
        pairedListView.setAdapter(mPairedDevicesArrayAdapter);
        pairedListView.setOnItemClickListener(mDeviceClickListener);
        ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
        newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
        newDevicesListView.setOnItemClickListener(mDeviceClickListener);
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        this.registerReceiver(mReceiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        this.registerReceiver(mReceiver, filter);
        mBtAdapter = BluetoothAdapter.getDefaultAdapter();
        Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
        if (pairedDevices.size() > 0) {
            findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n"
                        + device.getAddress());
            }
        } else {
            String noDevices = getResources().getText(R.string.none_paired)
                    .toString();
            mPairedDevicesArrayAdapter.add(noDevices);
        }
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mBtAdapter != null) {
            mBtAdapter.cancelDiscovery();
        }
        this.unregisterReceiver(mReceiver);
    }
    private void doDiscovery() {
        setProgressBarIndeterminateVisibility(true);
        setTitle(R.string.scanning);
        findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);
        if (mBtAdapter.isDiscovering()) {
            mBtAdapter.cancelDiscovery();
        }
        mBtAdapter.startDiscovery();
    }
    private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
        public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
            mBtAdapter.cancelDiscovery();
            String info = ((TextView) v).getText().toString();
            String address = info.substring(info.length() - 17);
            Intent intent = new Intent();
            intent.putExtra(EXTRA_DEVICE_ADDRESS, address);
            setResult(Activity.RESULT_OK, intent);
            finish();
        }
    };
    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent
                        .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    mNewDevicesArrayAdapter.add(device.getName() + "\n"
                            + device.getAddress());
                }
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                setProgressBarIndeterminateVisibility(false);
                setTitle(R.string.select_device);
                if (mNewDevicesArrayAdapter.getCount() == 0) {
                    String noDevices = getResources().getText(
                            R.string.none_found).toString();
                    mNewDevicesArrayAdapter.add(noDevices);
                }
            }
        }
    };
}