BluetoothCommService

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.Bluetooth;
using Java.Util;
using System.Threading;
using System.IO;

namespace MonoAndroidApplication1.Services
{
    public class BluetoothCommService
    {
        private UUID ServiceUUID = UUID.FromString( "00001101-0000-1000-8000-00805F9B34FB" );

        protected BluetoothAdapter _Adapter;
        protected Handler _Handler;

        protected Thread _ReadingThread = null;
        private bool _AbortReadingThread = false;

        public BluetoothCommService( Context context, Handler handler )
        {
            _Adapter = BluetoothAdapter.DefaultAdapter;
            _Handler = handler;
        }

        public const int STATE_NONE = 0;       // we're doing nothing
        public const int STATE_LISTEN = 1;     // now listening for incoming connections
        public const int STATE_CONNECTING = 2; // now initiating an outgoing connection
        public const int STATE_CONNECTED = 3;  // now connected to a remote device

        public void ConnectAsync( BluetoothDevice device, Action<BluetoothSocket> completedCallback )
        {
            _Adapter.CancelDiscovery();

            Thread thread = new Thread( new ParameterizedThreadStart( ConnectThreadWorker ) );
            thread.Start( new RequestState() { Device = device, Callback = completedCallback } );
        }

        private void ConnectThreadWorker( object objState )
        {
            RequestState state = (RequestState)objState;

            BluetoothSocket socket = TryConnect( state.Device, 0 );

            if ( state.Callback != null )
            {
                state.Callback( socket );
            }

            if ( socket != null )
            {
                // start reading thread
                _ReadingThread = new Thread( new ParameterizedThreadStart( ReadingThreadWorker ) );
                _ReadingThread.Start( socket );
            }
        }

        private void ReadingThreadWorker( object objSocket )
        {
            _AbortReadingThread = false;
            BluetoothSocket socket = (BluetoothSocket)objSocket;
            StreamReader reader = new StreamReader( socket.InputStream );
            char[] buffer = new char[ 1024 ];

            //SendText( socket, "$PFAL,MSG.VERSION.COMPLETE" );

            while ( !_AbortReadingThread )
            {
                try
                {
                    int n = reader.ReadBlock( buffer, 0, buffer.Length );

                    _Handler.ObtainMessage( 1, n, -1, buffer ).SendToTarget();
                }
                catch ( Java.IO.IOException )
                {
                    Android.Util.Log.Error( "BTCOMM", "disconnected" );
                    break;
                }
            }
        }

        private BluetoothSocket TryConnect( BluetoothDevice device, int retryCounter )
        {
            BluetoothSocket socket = null;

            try
            {
                socket = device.CreateRfcommSocketToServiceRecord( ServiceUUID );
            }
            catch ( Java.IO.IOException )
            {
                if ( retryCounter < 5 )
                {
                    return ( TryConnect( device, retryCounter + 1 ) );
                }
            }

            return ( socket );
        }

        public void Disconnect( BluetoothSocket socket )
        {
            _AbortReadingThread = true;
            socket.Close();
        }

        public void SendText( BluetoothSocket socket, string text )
        {
            try
            {
                StreamWriter writer = new StreamWriter( socket.OutputStream );
                writer.Write( text );
            }
            catch ( Java.IO.IOException )
            {
            }
        }

        private class RequestState
        {
            public BluetoothSocket Socket
            {
                get;
                set;
            }

            public BluetoothDevice Device
            {
                get;
                set;
            }

            public Action<BluetoothSocket> Callback
            {
                get;
                set;
            }
        }
    }
}