Xamarin OnCharacteristicChanged

Question

我正在使用 BLE 来发送和接收数据。

我可以将数据写入BLE，但不会收到回应"OnCharacteristicChanged"我在写入OnCharacteristicWrite时会收到bluetoothgatt WriteCharacteristic的回复。

请帮我修理一下。或建议我最佳做法或示例代码。 提前谢谢。

这是我的代码。

onDiscovered service
{
  string ser = "0003CDD0-0000-1000-8000-00805f9b0131";
                    string charId = "0003CDD2-0000-1000-8000-00805f9b0131";
                    bluetoothGatt = gatt;
                    //bleMTU = bluetoothGatt.RequestMtu(400);
                    mService = bluetoothGatt.GetService(UUID.FromString(ser));
                    charbt = mService.GetCharacteristic(UUID.FromString(charId));
                    bluetoothGatt.SetCharacteristicNotification(charbt, true);
}

Void writetosocket
{
byte[] smallPacket = new byte[numberOfBytes]; 
 charbt.SetValue(smallPacket);
charbt.WriteType = BluetoothGattCharacteristic.WriteTypeNoResponse;
 bool check = bluetoothGatt.WriteCharacteristic(charbt);
}

Answer 1

您似乎缺少订阅ReadCharacteristic。以下是我在自定义GattCallback中实现该部分的方法：

class GattCallback : BluetoothGattCallback
{
    public BluetoothGattCharacteristic ReadCharacteristic { get; set; }
    public BluetoothGattCharacteristic WriteCharacteristic { get; set; }

    public override void OnServicesDiscovered(BluetoothGatt gatt, GattStatus status)
    {
        var service = gatt.Services.FirstOrDefault(s => s.Uuid.ToString().Equals("0003CDD0-0000-1000-8000-00805f9b0131"));

        WriteCharacteristic = service.Characteristics[0]; //Find your WriteCharacteristic
        ReadCharacteristic = service.Characteristics[1]; //Find your ReadCharacteristic

        gatt.SetCharacteristicNotification(ReadCharacteristic, true);

        //Subscribe on ReadCharacteristic for communication
        var readCharacteristicDiscriptor = ReadCharacteristic.Descriptors[0];
        readCharacteristicDiscriptor.SetValue(BluetoothGattDescriptor.EnableIndicationValue.ToArray());

        gatt.WriteDescriptor(readCharacteristicDiscriptor);
    }
}