Android到IOS蓝牙聊天应用

Question

public class MainActivity extends AppCompatActivity {

    private BluetoothAdapter bluetoothAdapter;
    private BluetoothGatt gatt;
    private BluetoothGattCharacteristic inputCharacteristic;
    private TextView outputView;
    private EditText inputView;
    private static final int REQUEST_ENABLE_BT = 1;
    BluetoothAdapter.LeScanCallback leScanCallback;

    public void receiveMode(View v) {

        bluetoothAdapter.startLeScan(leScanCallback);
    }

    public void sendMessage(View v) {
        inputCharacteristic.setValue(inputView.getText().toString());
        gatt.writeCharacteristic(inputCharacteristic);
    }


    private final BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
        @Override
        public void onCharacteristicChanged(BluetoothGatt gatt, final BluetoothGattCharacteristic characteristic) {

            if (getString(R.string.outputUUID).equals(characteristic.getUuid().toString())) {
                final String value = characteristic.getStringValue(0);
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        outputView.setText(value);
                    }
                });

            }
        }
        @Override
        public void onConnectionStateChange(final BluetoothGatt gatt, final int status, final int newState) {
            MainActivity.this.gatt = gatt;
            if (newState == BluetoothProfile.STATE_CONNECTED) {
                try {
                    Thread.sleep(1500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                gatt.discoverServices();
            }

        }
        @Override
        public void onServicesDiscovered(BluetoothGatt gatt, int status) {
            List<BluetoothGattService> services = gatt.getServices();
            for (BluetoothGattService service : services) {
                List<BluetoothGattCharacteristic> characteristics = service.getCharacteristics();
                for (BluetoothGattCharacteristic characteristic : characteristics) {
                    if (getString(R.string.outputUUID).equals(characteristic.getUuid().toString())) {
                        try {
                            Thread.sleep(500);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        gatt.setCharacteristicNotification(characteristic, true);
                        BluetoothGattDescriptor descriptor = characteristic.getDescriptors().get(0);
                        if (descriptor != null) {
                            descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
                            gatt.writeDescriptor(descriptor);
                        }
                    } else if (getString(R.string.inputUUID).equals(characteristic.getUuid().toString())) {
                        try {
                            Thread.sleep(500);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        inputCharacteristic = characteristic;
                    }
                }
            }


        }
    };



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

        outputView = (TextView) findViewById(R.id.outputText);
        inputView = (EditText) findViewById(R.id.inputText);

        final BluetoothManager bluetoothManager =
                (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
        bluetoothAdapter = bluetoothManager.getAdapter();

        if (bluetoothAdapter != null && !bluetoothAdapter.isEnabled()) {
            Intent enableBtIntent = new
                    Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
        }

    }
}

这是我收到的错误消息：

08-02 11:36:06.470 311 88-31188/uk.ac.york.androidtoiosble d/BluetoothAdapter：startLeScan（）：null 08-02 11:36:06.470 311 88-31188/uk.ac.york.androidtoiosble e/BluetoothAdapter：startLeScan：null回调

Answer 1

对于初学者，您会得到一个空回调，因为您实际上从未创建过一个。

但是，要回答你的第二个问题

使用替代方法扫描设备？