使用android studio连接蓝牙中的配对设备

Question

我已经创建了一个应用程序来成功显示配对的设备，但无法连接到它。

我尝试了很多，但我得到“应用程序已停止工作”。在我的代码连接到已配对设备上的问题

请告知：

public class MainActivity extends AppCompatActivity { 

    public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); 
    BluetoothAdapter bt; 
    ArrayAdapter<String> listAdapter; 
    Set<BluetoothDevice> devicesArray; 
    ListView listview; 
    Button connectbutton; 
    Handler mHandler = new Handler(){ 
     @Override 
     public void handleMessage(Message msg) { 
      // TODO Auto-generated method stub 

      super.handleMessage(msg); 
        Toast.makeText(getApplicationContext(), "CONNECT", Toast.LENGTH_SHORT).show(); 

     } 
    }; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     init(); 
     if(bt==null){ 
      Toast.makeText(getApplicationContext(), "no bluetooth on device",Toast.LENGTH_SHORT).show(); 
      finish(); 

     } 
     else 
     { 
      if(!bt.isEnabled()){ 
       Intent intent=new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); 
       startActivityForResult(intent,1); 
      } 

     } 
     listview.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View arg1, int arg2, long arg3) { 

       Toast.makeText(getApplicationContext(), (CharSequence) parent.getItemAtPosition(arg2), Toast.LENGTH_SHORT).show(); 
       if(bt.isDiscovering()) 
       { 
        bt.cancelDiscovery(); 
       } 
       BluetoothDevice selectedDevice = (BluetoothDevice) parent.getItemAtPosition(arg2); 


      } 
     }); 
    } 

    public void onButtonClick(View v) 
    { 
     getpaireddevices(); 

    } 

    public void onButtonClick2(View v) 
    { 
     startdiscovery(); 
    } 

    private void getpaireddevices() { 
     devicesArray = bt.getBondedDevices(); 
     if (devicesArray.size() > 0) { 
      for (BluetoothDevice device : devicesArray) 
       listAdapter.add(device.getName()); 
     } 
    } 

    private void startdiscovery() 
    { 
     bt.cancelDiscovery(); 
     bt.startDiscovery(); 
    } 




    private void init() { 
     listview = (ListView)findViewById(R.id.listView);  
     connectbutton = (Button)findViewById(R.id.button); 
     listAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,0); 
     listview.setAdapter(listAdapter); 
     bt= BluetoothAdapter.getDefaultAdapter(); 
    } 

    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 
     if(resultCode == RESULT_CANCELED) 
     { 
      Toast.makeText(getApplicationContext(), "bluetooth must be turned on to continue",Toast.LENGTH_SHORT).show(); 
      finish(); 
     } 
    } 

Answer 1

当我希望得到连接的蓝牙设备的列表，我的应用程序AW好帮我，

Get List Of Paired Bluetooth Devices

在第一个链接，除了给你一个配对的设备列表它onclick，然后我用第二个链接（如何通过蓝牙发送图像）与我选择的设备进行通信

Sending Images Over Bluetooth In Android

例如：

class SendData extends Thread { 
private BluetoothDevice device = null; 
private BluetoothSocket btSocket = null; 
private OutputStream outStream = null; 

public SendData(){ 
device = mBluetoothAdapter.getRemoteDevice(address); 
try 
{ 
btSocket = device.createRfcommSocketToServiceRecord(MY_UUID); 
} 
catch (Exception e) { 
// TODO: handle exception 
} 
mBluetoothAdapter.cancelDiscovery(); 
try { 
btSocket.connect(); 
} catch (IOException e) { 
try { 
btSocket.close(); 
} catch (IOException e2) { 
} 
} 
Toast.makeText(getBaseContext(), "Connected to " + device.getName(), Toast.LENGTH_SHORT).show(); 
try { 
outStream = btSocket.getOutputStream(); 
} catch (IOException e) { 
} 
} 

public void sendMessage() 
{ 
try { 
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); 
Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.white); 
ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
bm.compress(Bitmap.CompressFormat.JPEG, 100,baos); //bm is the bitmap object 
byte[] b = baos.toByteArray(); 
Toast.makeText(getBaseContext(), String.valueOf(b.length), Toast.LENGTH_SHORT).show(); 
outStream.write(b); 
outStream.flush(); 
} catch (IOException e) { 
} 
} 
} 
} 

希望它可以帮助你！