android - Android API 20 是否允许支持蓝牙 LE 的设备充当外围设备？

Question

我正在使用以下代码将 Android 设备设置为外围设备，但它似乎无法正常工作。您知道 API 20 是否支持外设模式吗？

BluetoothGattServer mGattServer;
public void startPeripheralGattServer() {
        final BluetoothManager bluetoothManager =
                (BluetoothManager) this.getSystemService(Context.BLUETOOTH_SERVICE);

        mGattServer = bluetoothManager.openGattServer(getApplicationContext(), new BluetoothGattServerCallback() {

                @Override
                public void onCharacteristicReadRequest(BluetoothDevice device, int requestId,
                    int offset, BluetoothGattCharacteristic characteristic) {

                    if (mGattServer != null) {
                        mGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset, new byte[] { '1' });
                    }
                }
            });

        UUID serviceUUID = UUID.randomUUID();
        UUID characteristicUUID = UUID.randomUUID();
        UUID descriptorUUID = UUID.randomUUID();

        BluetoothGattCharacteristic characteristic = new BluetoothGattCharacteristic(characteristicUUID, BluetoothGattCharacteristic.PROPERTY_READ, BluetoothGattCharacteristic.PERMISSION_READ);
        characteristic.setValue(77, BluetoothGattCharacteristic.FORMAT_UINT8, 0);

        BluetoothGattDescriptor descriptor = new BluetoothGattDescriptor(descriptorUUID,    
                BluetoothGattDescriptor.PERMISSION_READ);

        characteristic.addDescriptor(descriptor);

        BluetoothGattService service = new BluetoothGattService(serviceUUID, 
                BluetoothGattService.SERVICE_TYPE_PRIMARY);
        service.addCharacteristic(characteristic);

        mGattServer.addService(service);
    }

Answer 1

基于此Google I/O video for Bluetooth Low Energy ，外设模式将从 Android API 20 (Android L) 及更高版本开始可用。