[Android] BluetoothDevice.ACTION_FOUND / 블루투스 디바이스 찾기 해도 BroadcastReceiver에 들어가지 않는 오류

mBluetoothAdapter.startDiscovery();
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadCastReceiver,discoverDevicesIntent);

 

를 통해 인텐트필터를 등록하고, 브로드캐스트에 해당 action을 받아도 broadcastlistener가 작동하지 않는 일이 발생했다. mBluetoothAdapter.ACTION_SCAN_MODE_CHANGED 이런거는 잘 되는데 왜 ACTION_FOUND만 안되는지 한참 고민하고 오타가 있는건가 찾았는데 답은 user에게 물어보는 별도의 권한을 줘야하는 것이었다. 

 

1. manifest에 권한 추가

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

 

2.아래와 같은 함수를 작성한 후, startDiscovery 하기 전에 checkBTPermissions()를 호출하면 된다. 

@RequiresApi(api = Build.VERSION_CODES.M)
    private void checkBTPermissions(){
        if(Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
            int permissionCheck = this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
            permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
            if(permissionCheck!=0){
                this.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.ACCESS_COARSE_LOCATION},1001);
            }
            else{
                Log.d("checkPermission", "No need to check permissions. SDK version < LoLLIPOP");
            }
        }
    }

** checkBTPermission()을 호출하면 생기는 빨간줄은 버전때문에 생기는 것인데 무시해도 된다고 한다. 

 

---전체 코드 

//onCreate 안에
 btnFindDiscover.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                bluetoothDiscover();
            }
        });
        
        
//bluetoothDiscover()
public void bluetoothDiscover(){
        if(mBluetoothAdapter.isDiscovering()){ //already discovering > cancel > discover
            mBluetoothAdapter.cancelDiscovery();
            Toast.makeText(getApplicationContext(), "Canceling discovery", Toast.LENGTH_SHORT).show();

            checkBTPermissions(); //check for permissions

            mBluetoothAdapter.startDiscovery();
            IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
            registerReceiver(mBroadCastReceiver,discoverDevicesIntent);
        }

        else if(!mBluetoothAdapter.isDiscovering()){
            checkBTPermissions();
            Toast.makeText(getApplicationContext(), "Starting discovery", Toast.LENGTH_SHORT).show();

            mBluetoothAdapter.startDiscovery();
            IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
            registerReceiver(mBroadCastReceiver,discoverDevicesIntent);

        }
    }
    
    
//checkBTPermissions()
@RequiresApi(api = Build.VERSION_CODES.M)
    private void checkBTPermissions(){
        if(Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
            int permissionCheck = this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
            permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATION");
            if(permissionCheck!=0){
                this.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.ACCESS_COARSE_LOCATION},1001);
            }
            else{
                Log.d("checkPermission", "No need to check permissions. SDK version < LoLLIPOP");
            }
        }
    }
    
//BroadcastReceiver
private final BroadcastReceiver mBroadCastReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
           
            if(action.equals(BluetoothDevice.ACTION_FOUND)){
                //get devices
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                mBTdevices.add(device);
                //attach device to adapter & set list
                mDeviceListAdapter = new DeviceListAdapter(context,R.layout.device_adapter_view, mBTdevices);
                newDevicesList.setAdapter(mDeviceListAdapter);
            }//end if

        }//end onReceive
    };
    

 

 

**참고

stackoverrun.com/ko/q/10525893

android - 안드로이드 6.0 - 블루투스 - 어떤 코드가 Action_Found이 인터넷에 표시된 예에서도, 의도

stackoverrun.com/ko/q/10614409

android - 블루투스 ACTION_FOUND broadcastReceiver가 작동하지 않습니다.