问c#蓝牙乐写配置错误- ValueChanged从未调用

EN

private async Task ConnectToWatcher(DeviceInformation deviceInfo) {
        try {
            // get the device
            BluetoothLEDevice device = await BluetoothLEDevice.FromIdAsync(deviceInfo.Id);

            // get the GATT service
            Thread.Sleep(150);
            var gattServicesResult = await device.GetGattServicesForUuidAsync(new Guid(RX_SERVICE_UUID));
            service = gattServicesResult.Services[0];

            // get the GATT characteristic
            Thread.Sleep(150);
            var gattCharacteristicsResult = await service.GetCharacteristicsForUuidAsync(new Guid(RX_CHAR_UUID));
            characteristic = gattCharacteristicsResult.Characteristics[0];

            // register for notifications
            Thread.Sleep(150);

            characteristic.ValueChanged += (sender, args) => {
                Debug.WriteLine($"[{device.Name}] Received notification containing {args.CharacteristicValue.Length} bytes");
            };

            GattWriteResult result =
            await characteristic.WriteClientCharacteristicConfigurationDescriptorWithResultAsync(GattClientCharacteristicConfigurationDescriptorValue.Notify);
            Debug.WriteLine($"Characteristics write result: status={result.Status}, protocolError={result.ProtocolError}");

        } catch (Exception ex) when ((uint)ex.HResult == 0x800710df) {
            Debug.WriteLine("bluetooth error 1");
            // ERROR_DEVICE_NOT_AVAILABLE because the Bluetooth radio is not on.
        }
    }

 Debug.WriteLine($"Characteristics write result: status={result.Status}, protocolError={result.ProtocolError}"