1.权限
在AndroidManifest.xml中申请权限:

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

2.界面
聊天界面:Listview显示对话,EditText编辑信息,Button发送信息
搜索设备界面：主要是Listview和TextView

3.代码
DeviceList:蓝牙搜索设备
蓝牙搜索主要是要实现一个BroadcastReceiver 广播接收者。
首先注册广播，添加蓝牙设备ACTION_FOUND。
之后就是广播接收，开启广播搜索之后，如果找到设备，接受到ACTOIN_FOUND的信息，把BluetoothDevice.EXTRA_DEVICE中的搜索信息，显示到屏幕上。如果没有找到设备，DISCOVERY_FINISHED，结束搜索。

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)){progressBar.setVisibility(View.GONE);Toast.makeText(DeviceList.this,"搜索完毕", Toast.LENGTH_SHORT).show();if(mNewDevicesArrayAdapter.getCount()==0){String noDevices=getResources().getText(R.string.none_found).toString();mNewDevicesArrayAdapter.add(noDevices);}}
}

ChatService:蓝牙连接
创建监听线程，准备接受新连接。使用阻塞方式，使用BluetoothServerSocket accept函数，收到连接，则保持此连接传给 ConnectedThread

 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(){BluetoothSocket socket= null;while(mState != STATE_CONNECTED){try{socket = mmServerSocket.accept();}catch (IOException e) {break;}if(socket != null){connected(socket,socket.getRemoteDevice());try{mmServerSocket.close();}catch (IOException e){}}}}public void cancel(){try{mmServerSocket.close();}catch (IOException e){}}
}

createRfcommSocketToServiceRecord 根据UUID 发起连接，连接成功则将连接传入ConnectedThread

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(){// Cancel discovery because it will slow down the connectionmAdapter.cancelDiscovery();try{mmSocket.connect();}catch (IOException e){connectionFailed();try{mmSocket.close();}catch (IOException e2){}      return;}synchronized(ChatService.this){mConnectedThread = null;}connected(mmSocket,mmDevice);}}

管理连接好的双方，进行数据通信。输入输出流，接收数据，发送数据

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 finaltry{tmpIn=mmSocket.getInputStream();tmpOut=mmSocket.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);}catch (IOException e){Log.d("BlueToothChat","Send Fail");}mHandler.obtainMessage(BlueToothChat.MESSAGE_WRITE,buffer).sendToTarget();}public void cancel(){try{mmSocket.close();}catch (IOException e){}}
}

BlueToothChat:蓝牙聊天
使用Handler对象在UI主线程与子线程之间传递消息

private final Handler mHandler=new Handler(){@Overridepublic void handleMessage(Message msg){switch (msg.what){case MESSAGE_STATE_CHANGE:switch (msg.arg1){case ChatService.STATE_CONNECTED:mConversationArrayAdapter.clear();break;case ChatService.STATE_CONNECTING:break;case ChatService.STATE_LISTEN:case ChatService.STATE_NONE: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.arg1);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;}}
};

部分代码放在码云
码云链接:https://gitee.com/kadd/android/tree/master/BlueTooth