C# concise asynchronous TcpClient

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Diagnostics;

namespace AsyncTcpClient
{
    class Program
    {
        TcpClient _client = null;
        NetworkStream _stream;
        byte[] _buf = new byte[2048];
        StringBuilder _msg = new StringBuilder();

        void OnRead(IAsyncResult ar)
        {
            int nRead = _stream.EndRead(ar);
            string data = Encoding.ASCII.GetString(_buf, 0, nRead);

            int lineno = 1;
            for (int k = 0; k < data.Length; ++k)
            {
                if (data[k] == '\n')
                {
                    if (_msg.Length > 0)
                    {
                        if (_msg[_msg.Length - 1] == '\r') _msg.Remove(_msg.Length - 1, 1);
                        if (_msg.Length > 0)
                            Console.WriteLine("<<<< [{0}] {1}", lineno++, _msg.ToString());
                        _msg.Clear();
                    }
                }
                else
                    _msg.Append(data[k]);
            }

            _stream.BeginRead(_buf, 0, _buf.Length, OnRead, null);
        }

        public void Run()
        {
            string host = "www.google.com";
            int port = 80;

            _client = new TcpClient(host, port);

            if (!_client.Connected)
            {
                Console.WriteLine("Fail to connect to {0}:{1}", host, port);
                return;
            }

            _stream = _client.GetStream();
            _msg.Capacity = 4098;

            _stream.BeginRead(_buf, 0, _buf.Length, OnRead, null);

            string cmd = "GET\n";
            byte[] raw = Encoding.ASCII.GetBytes(cmd);
            Console.WriteLine("send " + cmd);
            _stream.Write(raw, 0, raw.Length);

            Console.ReadLine();
        }

        static void Main(string[] args)
        {
            new Program().Run();
        }
    }
}