Bluetooth Example

   private static final int REQUEST_ENABLE_BT = 1;
   private Button onBtn;
   private Button offBtn;
   private Button listBtn;
   private Button findBtn;
   private TextView text;
   private BluetoothAdapter myBluetoothAdapter;
   private Set<BluetoothDevice> pairedDevices;
   private ListView myListView;
   private ArrayAdapter<String> BTArrayAdapter;
   
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
       
      // take an instance of BluetoothAdapter - Bluetooth radio
      myBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
      if(myBluetoothAdapter == null) {
          onBtn.setEnabled(false);
          offBtn.setEnabled(false);
          listBtn.setEnabled(false);
          findBtn.setEnabled(false);
          text.setText("Status: not supported");
           
          Toast.makeText(getApplicationContext(),"Your device does not support Bluetooth",
                 Toast.LENGTH_LONG).show();
      } else {
          text = (TextView) findViewById(R.id.text);
          onBtn = (Button)findViewById(R.id.turnOn);
          onBtn.setOnClickListener(new OnClickListener() {
             
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                on(v);
            }
          });
           
          offBtn = (Button)findViewById(R.id.turnOff);
          offBtn.setOnClickListener(new OnClickListener() {
             
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                off(v);
            }
          });
           
          listBtn = (Button)findViewById(R.id.paired);
          listBtn.setOnClickListener(new OnClickListener() {
             
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                list(v);
            }
          });
           
          findBtn = (Button)findViewById(R.id.search);
          findBtn.setOnClickListener(new OnClickListener() {
             
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                find(v);
            }
          });
         
          myListView = (ListView)findViewById(R.id.listView1);
     
          // create the arrayAdapter that contains the BTDevices, and set it to the ListView
          BTArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1);
          myListView.setAdapter(BTArrayAdapter);
      }
   }
 
   public void on(View view){
      if (!myBluetoothAdapter.isEnabled()) {
         Intent turnOnIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
         startActivityForResult(turnOnIntent, REQUEST_ENABLE_BT);
 
         Toast.makeText(getApplicationContext(),"Bluetooth turned on" ,
                 Toast.LENGTH_LONG).show();
      }
      else{
         Toast.makeText(getApplicationContext(),"Bluetooth is already on",
                 Toast.LENGTH_LONG).show();
      }
   }
    
   @Override
   protected void onActivityResult(int requestCode, int resultCode, Intent data) {
       // TODO Auto-generated method stub
       if(requestCode == REQUEST_ENABLE_BT){
           if(myBluetoothAdapter.isEnabled()) {
               text.setText("Status: Enabled");
           } else {  
               text.setText("Status: Disabled");
           }
       }
   }
    
   public void list(View view){
      // get paired devices
      pairedDevices = myBluetoothAdapter.getBondedDevices();
       
      // put it's one to the adapter
      for(BluetoothDevice device : pairedDevices)
          BTArrayAdapter.add(device.getName()+ "\n" + device.getAddress());
 
      Toast.makeText(getApplicationContext(),"Show Paired Devices",
              Toast.LENGTH_SHORT).show();
       
   }
    
   final BroadcastReceiver bReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                 // Get the BluetoothDevice object from the Intent
                 BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                 // add the name and the MAC address of the object to the arrayAdapter
                 BTArrayAdapter.add(device.getName() + "\n" + device.getAddress());
                 BTArrayAdapter.notifyDataSetChanged();
            }
        }
    };
     
   public void find(View view) {
       if (myBluetoothAdapter.isDiscovering()) {
           // the button is pressed when it discovers, so cancel the discovery
           myBluetoothAdapter.cancelDiscovery();
       }
       else {
            BTArrayAdapter.clear();
            myBluetoothAdapter.startDiscovery();
             
            registerReceiver(bReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));   
        }   
   }
    
   public void off(View view){
      myBluetoothAdapter.disable();
      text.setText("Status: Disconnected");
       
      Toast.makeText(getApplicationContext(),"Bluetooth turned off",
              Toast.LENGTH_LONG).show();
   }
    
   @Override
   protected void onDestroy() {
       // TODO Auto-generated method stub
       super.onDestroy();
       unregisterReceiver(bReceiver);
   }