Xamarin / MAUI

        public IConnectionService GetConnectionServiceInstance(ConnectionType ct)

        IConnectionService GetConnectionServiceInstance(ConnectionType ct);

            ConnectionService = DependencyService.Get<IConnectionServiceProvider>().GetConnectionServiceInstance(ConnectionType.Intern);

using System;

using System.Collections.Generic;

using System.Text;

using System.Threading.Tasks;

using TestXamConnections.Connection;

using TestXamConnections.Helper;

using Xamarin.Forms;

namespace TestXamConnections.Models

{

    public class BluetoothReader : Device

    {

        private IConnectionService ConnectionService { get; set; }

        public EventHandler<byte[]> BluetoothDataReceivedEvent { get; set; }

        public BluetoothReader(Device device)

        {

            Name = device.Name;

            MACAddress = device.MACAddress;

            ConnectionService = DependencyService.Get<IConnectionServiceProvider>().GetConnectionServiceInstance(ConnectionType.Bluetooth);

            ConnectionService.DataReceivedEvent += BluetoothDataReceived;

        }

        private void BluetoothDataReceived(object sender, byte[] e)

        {

            BluetoothDataReceivedEvent.Invoke(this, e);

        }

        public async Task<bool> ConnectToBTReaderAsync()

        {

            Dictionary<string, string> param = new Dictionary<string, string>()

            {

                { ConnectionConstants.MAC_ADDR_KEY, MACAddress }

            };

            bool ret = await ConnectionService.Connect(param);

            return ret;

        }

    }

}

            ConnectionService = DependencyService.Get<IConnectionServiceProvider>().GetConnectionServiceInstance(ConnectionType.Bluetooth);

            _ = await ConnectionService.Connect(param);

    <Compile Update="Views\BluetoothReaderView.xaml.cs">

      <DependentUpon>BluetoothReaderView.xaml</DependentUpon>

    </Compile>

    <EmbeddedResource Update="Views\BluetoothReaderView.xaml">

      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>

    </EmbeddedResource>

            _ = await CheckAndRequestLocationPermission();

using System;

using System.Collections.Generic;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Input;

using TestXamConnections.Models;

using Xamarin.Forms;

namespace TestXamConnections.ViewModels

{

    public class BluetoothReaderViewModel : ViewModelBase

    {

        private BluetoothReader btReader;

        private bool isVisibleData;

        private string data;

        private string connectionIndicator;

        private string ciColor;

        public string CIColor

        {

            get => ciColor;

            set => SetProperty(ref ciColor, value);

        }

        public string ConnectionIndicator

        {

            get => connectionIndicator;

            set => SetProperty(ref connectionIndicator, value);

        }

        public string Data

        {

            get => data;

            set => SetProperty(ref data, value);

        }

        public bool IsVisibleData

        {

            get => isVisibleData;

            set => SetProperty(ref isVisibleData, value);

        }

        public BluetoothReader BTReader

        {

            get => btReader;

            set => SetProperty(ref btReader, value);

        }

        public async Task<bool> ConnectToDevice()

        {

            if (await BTReader.ConnectToBTReaderAsync())

            {

                ConnectionIndicator = "Connecté";

                CIColor = "Green";

                return true;

            }

            else

            {

                ConnectionIndicator = "Non Connecté";

                CIColor = "Red";

                return false;

            }

        }

        public ICommand ConnectToDeviceCommand { get; private set; }

        public BluetoothReaderViewModel(Models.Device device)

        {

            CIColor = "Red";

            ConnectionIndicator = "Non connecté";

            IsVisibleData = false;

            BTReader = new BluetoothReader(device);

            ConnectToDeviceCommand = new Command(async () => await ConnectToDevice());

            BTReader.BluetoothDataReceivedEvent += DataReceived;

        }

        private void DataReceived(object sender, byte[] e)

        {

            IsVisibleData = true;

            Data += Encoding.ASCII.GetString(e) + "\n";

        }

    }

}

            // Si c'est le scanner HoneyWell

            else if (Device.MACAddress == "00:10:20:30:92:7D")

            {

                await Application.Current.MainPage.Navigation.PushAsync(new BluetoothReaderView(Device));

            }

<?xml version="1.0" encoding="UTF-8" ?>

<ContentPage

    x:Class="TestXamConnections.Views.BluetoothReaderView"

    xmlns="http://xamarin.com/schemas/2014/forms"

    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"

    xmlns:xe="clr-namespace:XamEffects;assembly=XamEffects">

    <ContentPage.Content>

        <StackLayout

            Padding="10"

            BackgroundColor="#001729"

            VerticalOptions="FillAndExpand">

            <StackLayout VerticalOptions="CenterAndExpand">

                <Frame

                    Padding="0"

                    BackgroundColor="Transparent"

                    BorderColor="#4f5a64"

                    CornerRadius="5"

                    HasShadow="False"

                    HorizontalOptions="Center"

                    VerticalOptions="CenterAndExpand"

                    WidthRequest="250">

                    <StackLayout Spacing="0">

                        <StackLayout Margin="0,10">

                            <Label

                                Margin="0"

                                FontAttributes="Bold"

                                FontSize="28"

                                HorizontalOptions="CenterAndExpand"

                                HorizontalTextAlignment="Center"

                                Text="{Binding BTReader.Name}"

                                TextColor="White"

                                VerticalOptions="CenterAndExpand" />

                            <Label

                                Margin="0"

                                FontAttributes="Italic"

                                FontSize="12"

                                HorizontalOptions="CenterAndExpand"

                                HorizontalTextAlignment="Center"

                                Text="{Binding BTReader.MACAddress}"

                                TextColor="DarkGray"

                                VerticalOptions="CenterAndExpand" />

                        </StackLayout>

                        <!--  Bouton Connect  -->

                        <xe:BorderView

                            Margin="0,10,0,20"

                            xe:Commands.Tap="{Binding ConnectToDeviceCommand}"

                            xe:TouchEffect.Color="#0060a8"

                            BackgroundColor="#003266"

                            CornerRadius="65"

                            HorizontalOptions="Center">

                            <StackLayout Padding="15,10">

                                <Label

                                    FontSize="16"

                                    HorizontalOptions="Center"

                                    Text="Connect"

                                    TextColor="#34a9ff" />

                            </StackLayout>

                        </xe:BorderView>

                        <Label

                            Margin="0,0,0,20"

                            FontAttributes="Bold"

                            FontSize="Medium"

                            HorizontalOptions="CenterAndExpand"

                            Text="{Binding ConnectionIndicator}"

                            TextColor="{Binding CIColor}"

                            VerticalOptions="CenterAndExpand" />

                    </StackLayout>

                </Frame>

                <Frame

                    Padding="0"

                    BackgroundColor="Transparent"

                    BorderColor="#4f5a64"

                    CornerRadius="5"

                    HasShadow="False"

                    HorizontalOptions="Center"

                    IsVisible="{Binding IsVisibleData}"

                    VerticalOptions="CenterAndExpand"

                    WidthRequest="200">

                    <StackLayout HorizontalOptions="CenterAndExpand">

                        <Label

                            FontAttributes="Bold"

                            FontSize="18"

                            HorizontalTextAlignment="Center"

                            Text="Received Data"

                            TextColor="White" />

                        <Label

                            FontAttributes="Italic"

                            FontSize="14"

                            HorizontalTextAlignment="Center"

                            Text="{Binding Data}"

                            TextColor="DarkGray" />

                    </StackLayout>

                </Frame>

            </StackLayout>

        </StackLayout>

    </ContentPage.Content>

</ContentPage>

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using TestXamConnections.ViewModels;

using Xamarin.Forms;

using Xamarin.Forms.Xaml;

namespace TestXamConnections.Views

{

    [XamlCompilation(XamlCompilationOptions.Compile)]

    public partial class BluetoothReaderView : ContentPage

    {

        public BluetoothReaderView(Models.Device device)

        {

            InitializeComponent();

            BindingContext = new BluetoothReaderViewModel(device);

        }

    }

}