Android bluetooth comunication

Question

私は、Bluetoothから他のBluetoothデバイスに文字列を送信するプロジェクトを作成します。私の質問は、もし私が最初のアクティビティでBluetoothデバイスに接続すると、2回目のアクティビティでもう一度それを作る必要があるのですか？

private ProgressDialog progress; 
public BluetoothAdapter myBluetooth = null; 
public static BluetoothSocket btSocket = null; 
private boolean isBtConnected = false; 
static final UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); 
@Override 
protected void onCreate(Bundle savedInstanceState) 
    { 
    super.onCreate(savedInstanceState); 

    Intent newint = getIntent(); 
    address = newint.getStringExtra(DeviceList.EXTRA_ADDRESS); 

    setContentView(R.layout.activity_led_vent_control); 
    init(); 

    leds1 = (Switch) findViewById(R.id.switch1); 
    leds2 = (Switch) findViewById(R.id.switch2); 
    leds3 = (Switch) findViewById(R.id.switch3); 
    leds4 = (Switch) findViewById(R.id.switch4); 
    leds5 = (Switch) findViewById(R.id.switch5); 
    brightness = (SeekBar)findViewById(R.id.seekBar); 
    lumn=(TextView)findViewById(R.id.lumn); 
    btnDis=(Button)findViewById(R.id.btnDis); 


    new ConnectBT().execute(); //Call the class to connect 

    //commands to be sent to bluetooth 
    leds1.setOnClickListener(new View.OnClickListener() 
    { 
     @Override 
     public void onClick(View v) 
     { 
      if(leds1.isChecked()) 
      turnOnLed1();  //method to turn on 
      else turnOffLed1(); 
     } 
    }); 
    } 
    private void turnOnLed1() 
{ 
    if (btSocket!=null) 
    { 
     try 
     { 
      btSocket.getOutputStream().write("A".toString().getBytes()); 
      l1=true; 
     } 
     catch (IOException e) 
     { 
      msg("Error"); 
     } 
    } 
} 

Answer 1

はここにあなたの `ConnectBT（）`クラスに依存し、私のConnectBTクラス

private class ConnectBT extends AsyncTask<Void, Void, Void> // UI thread 
{ 
    private boolean ConnectSuccess = true; //if it's here, it's almost connected 

    @Override 
    protected void onPreExecute() 
    { 
     progress = ProgressDialog.show(ledVentControl.this, "Свързва се...", "Моля изчакайте!!!"); //show a progress dialog 
    } 

    @Override 
    protected Void doInBackground(Void... devices) //while the progress dialog is shown, the connection is done in background 
    { 
     try 
     { 
      if (btSocket == null || !isBtConnected) 
      { 
       myBluetooth = BluetoothAdapter.getDefaultAdapter();//get the mobile bluetooth device 
       BluetoothDevice dispositivo = myBluetooth.getRemoteDevice(address);//connects to the device's address and checks if it's available 
       btSocket = dispositivo.createInsecureRfcommSocketToServiceRecord(myUUID);//create a RFCOMM (SPP) connection 
       BluetoothAdapter.getDefaultAdapter().cancelDiscovery(); 
       btSocket.connect();//start connection 
      } 
     } 
     catch (IOException e) 
     { 
      ConnectSuccess = false;//if the try failed, you can check the exception here 
     } 
     return null; 
    }