如何使用异步任务以编程方式检查蓝牙是否已与其他设备连接？

Question

I need to check whether any device is connected and communicating to my device via bluetooth in doInBackground method in Async Task. If connected/communicating - display toast message as "Connected". if not display as "No device connected".

I've searched everywhere, but no answers satisfied my requirements.

Answer 1

I do not know your problem in detail, but my Solution would be the BroadhastReceiver for Bluetooth Adapter.

public class AnyActivity extends AppCompatActivity {

private BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
private static boolean isConnected = false;
private static boolean isConnecting = false;
private static boolean isDisdconected = false;

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_any);

        IntentFilter BT_ConState_filter  = new 
        IntentFilter(BluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED);

        this.registerReceiver(BR_BT_ConState, BT_ConState_filter);
}

BroadcastReceiver BR_BT_ConState =new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action_BR_BT_ConState =intent.getAction();
            int iBR_BT_ConState_state = intent.getIntExtra(BluetoothAdapter.EXTRA_CONNECTION_STATE, mBluetoothAdapter.ERROR);

            if (action_BR_BT_ConState.equals(mBluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED))
            {
                switch (iBR_BT_ConState_state) {
                    case BluetoothAdapter.STATE_CONNECTING:
                        Toast.makeText(this, "Connecting" ,Toast.LENGTH_SHORT).show();
                        isConnected = false;
                        isConnecting = true;
                        isDisdconected = false;
                        break;

                    case BluetoothAdapter.STATE_CONNECTED:
                        Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show();
                        isConnected = true;
                        isConnecting = false;
                        isDisdconected = false;
                        break;

                    case BluetoothAdapter.STATE_DISCONNECTED:
                        Toast.makeText(this, "Disconected", Toast.LENGTH_SHORT).show();
                        isConnected = false;
                        isConnecting = false;
                        isDisdconected = true;
                        break;
                }
            }
        }
    };

public static boolean isConnected(){
return isConnected;
}

public static boolean isDisConnected(){
return isDisConnected;
}

public static boolean isConnecting(){
return isDisConnected;
}

@Override
    protected void onDestroy(){
        super.onDestroy();
        context.unregisterReceiver(BR_BT_ConState);
    }
}

If you tell me what you want to do exactly, for example: Run Some Code depending on state, Execute some TextView Changes, Or something like a callback Method,

or what else, I can try to help you even more.

What I did now is creating some static functions you should be able to call in your AsynkTask, just call AnyActivity.isConnected() and you get the current state of the BluetoothAdapter returned.

Answer 2

are you talking abou ble gatt? it yes then create a callback

    private final BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
        switch (newState) {
            case BluetoothProfile.STATE_DISCONNECTED:

                break;

            case BluetoothProfile.STATE_CONNECTING:

                break;

            case BluetoothProfile.STATE_CONNECTED:

                break;
        }
    }