Xamarin / MAUI

using Android.Bluetooth;

using Java.Util;

using System.IO;

using System.Threading;

using System.Threading.Tasks;

using TeoTestBluetooth.Droid.Utils;

using TeoTestBluetooth.Models;

using TestTeoBluetooth.Connection;

    public class BluetoothConnection : IBluetoothConnectionService

        private readonly BluetoothAdapter bluetoothAdapter;

        private Thread listeningThread;

        private BluetoothSocket socket;

        private readonly string sppUUID = "00001101-0000-1000-8000-00805f9b34fb";

        public BluetoothConnection()

        { 

            bluetoothAdapter = BluetoothAdapter.DefaultAdapter;

        }

        public async Task<bool> Connect(Device btDevice)

        {

            try

            {

                // Si jamais on est en train de scanner

                // On annule le scan

                if (bluetoothAdapter.IsDiscovering)

                {

                    bluetoothAdapter.CancelDiscovery();

                }

                BluetoothDevice droidBtDevice = bluetoothAdapter.GetRemoteDevice(btDevice.MACAddress);

                //Android.Bluetooth.BluetoothDevice droidBtDevice = adapter.BondedDevices.FirstOrDefault(x => (x.Address == bluetoothDevice.Address));

                if (droidBtDevice != null)

                {

                    // Si le socket est occupé pour une autre connexion

                    // On ferme la connexion existante

                    if (socket != null)

                    {

                        await CloseConnection();

                    }

                    // Creation du canal RFCOMM (non sécurisé)

                    socket = droidBtDevice.CreateInsecureRfcommSocketToServiceRecord(UUID.FromString(sppUUID));

                    CancellationTokenSource cts = new CancellationTokenSource();

                    cts.CancelAfter(50000);

                    await socket.ConnectAsync().WithCancellation(cts.Token);

                    if (listeningThread != null) listeningThread.Abort();

                    listeningThread = new Thread(async delagate => await ListeningAsync());

                    listeningThread.Start();

                    return true;

                }

            }

            catch (Exception ex)

            {

                System.Diagnostics.Debug.WriteLine(ex);

            }

            return false;

        }

        // Fonction d'écoute pour le Thread d'écoute

        private async Task ListeningAsync()

        {

            try

            {

                byte[] buffer = new byte[1024];

                while (socket.IsConnected)

                {

                    int byteAvailable = await socket.InputStream.ReadAsync(buffer, 0, buffer.Length);

                    // Resize the byte array 

                    byte[] filledBuffer = buffer.Take(byteAvailable).ToArray();

                    Application.SynchronizationContext.Post(_ => { OnDataReceived(filledBuffer); }, null);

                }

            }

            catch (IOException ex)

            {

                System.Diagnostics.Debug.WriteLine(ex);

            }

            catch (ThreadAbortException taEx)

            {

                System.Diagnostics.Debug.WriteLine(taEx);

            }

            catch (Exception ex)

            {

                System.Diagnostics.Debug.WriteLine(ex);

            }

        }

        public EventHandler<string> DataReceivedEvent { get; set; }

        private string _bufferedData;

        /* 

         * Fonction appelée à la reception de données

         * Trigger l'evenement DataReceivedEvent

         * 

         * IMPORTANT: Les trames peuvent arriver découpées,

         * Donc les données sont gardées dans un buffer d'envoi

         * nommé _bufferedData

         */

        private void OnDataReceived(byte[] buffer)

        {

            // Si le premier character est 2 (ASCII: STX)

            // Alors c'est le début de la trame.

            if (buffer[0] == 2)

            {

                _bufferedData = "";

                // Si character seul on quitte

                if (buffer.Length == 1)

                {

                    return;

                }

                // On enlève STX

                buffer = buffer.Skip(1).ToArray();

                // On mets le début de la trame dans buffer d'envoi

                _bufferedData += Encoding.ASCII.GetString(buffer);

            }

            // Si le dernier character est 13 (ASCII: CR)

            // Alors la trame est terminée

            if (buffer[^1] == 13)

            {

                // On enlève CR

                buffer = buffer.SkipLast(1).ToArray();

                // Conversion en chaîne de caractères

                // Et on complète le buffer d'envoi

                _bufferedData += Encoding.ASCII.GetString(buffer);

                // Trigger evènement

                DataReceivedEvent.Invoke(this, _bufferedData);

            }

        }

        private Task<bool> CloseConnection()

        {

            while (socket.IsConnected) socket.Close();

            return Task.FromResult(true);

        }

        public Task<bool> SendCommand(byte[] hexValues)

        {

            if (socket.IsConnected == false)

            {

                return Task.FromResult(false);

            }

            else

            {

                // Envoi de la commande

                socket.OutputStream.Write(hexValues, 0, hexValues.Length);

                socket.OutputStream.Flush();

            }

            return Task.FromResult(true);

        }

using System.Threading.Tasks;

using TeoTestBluetooth.Models;

using TestTeoBluetooth.Connection;

    public class InternConnection : IConnectionService

        public EventHandler<string> DataReceivedEvent { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }

        public Task<bool> Connect(Device device)

        {

            throw new NotImplementedException();

        }

        public Task<bool> SendCommand(byte[] hexValues)

        {

            throw new NotImplementedException();

        }

using TestBLE.Droid.Connection;

using TestTeoBluetooth.Connection;

            Forms.Init(this, savedInstanceState);

            DependencyService.Register<IConnectionService, BluetoothConnection>();

            DependencyService.Register<IConnectionService, InternConnection>();

                    var btDevice = new Models.Device

        public ObservableCollection<Device> FoundDevices = new ObservableCollection<Device>();

            FoundDevices = new ObservableCollection<Device>();

        public async Task<bool> Connect(Device btDevice)

        private async Task ListeningAsync(Device btDevice)

                FoundDevices.Add(new Device() { Name = e.Name, MACAddress = e.Address });

        public ObservableCollection<Device> DeviceList { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }

        public Task<bool> Pair(Device bluetoothDevice)

        public Task<bool> Disconnect(Device bluetoothDevice)

        public ICollection<Device> GetBondedDevices()

            ICollection<Device> ret = new ObservableCollection<Device>();

                Device toAddItem = new Device

using System;

using System.Collections.Generic;

using System.Text;

using System.Threading.Tasks;

using TeoTestBluetooth.Models;

namespace TestTeoBluetooth.Connection

{

    public enum ConnectionType

    {

        Intern,

        Bluetooth,

        Wifi

    }

    public interface IBluetoothConnectionService : IConnectionService

    {

    }

}

using System;

using System.Collections.Generic;

using System.Text;

using System.Threading.Tasks;

using TeoTestBluetooth.Models;

namespace TestTeoBluetooth.Connection

{

    public interface IConnectionService

    {

        Task<bool> Connect(Device device);

        Task<bool> SendCommand(byte[] hexValues);

        EventHandler<string> DataReceivedEvent { get; set; }

    }

}

using System;

using System.Collections.Generic;

using System.Text;

namespace TeoTestBluetooth.Models

{

    public class Device

    {

        public string Name { get; set; }

        public string MACAddress { get; set; }

        public override string ToString()

        {

            return Name + ":" + MACAddress;

        }

    }

}

        Task<bool> Pair(Device bluetoothDevice);

        Task<bool> Connect(Device bluetoothDevice);

        Task<bool> Disconnect(Device bluetoothDevice);

        ICollection<Device> GetBondedDevices();

        ObservableCollection<Device> DeviceList { get; set; }

            foreach (Models.Device bondedDevice in BluetoothService.GetBondedDevices())

        private Models.Device device;

        public Models.Device Device

        public DeviceItemViewModel(Models.Device device)

        public void Update(Models.Device newDevice = null)

        private Models.Device device;

        public Models.Device Device

        public DeviceViewModel(Models.Device device)

        public DeviceView(Models.Device device)