C# simple http download sample

Downloader Sample

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.Sockets;
using System.Net;

namespace ConsoleApplication1
{
    class Program
    {
        //d41d8cd98f0b24e980998ecf8427e
        static string B2S(byte[] bs)
        {
            var sb = new StringBuilder((int)(bs.Length * .5f));

            foreach (var c in bs)
            {
                sb.AppendFormat("{0:x}", c);
            }
            return sb.ToString();
        }

        static void Main(string[] args)
        {
            var buf = new byte[1024 * 512];
            var url = new Uri("http://foodatcoa.sinaapp.com/WebPlayer/bundle/data.asset");
            var req = (HttpWebRequest)WebRequest.Create(url);// HttpWebRequest.CreateHttp(url);
            var md5 = System.Security.Cryptography.MD5.Create();

            req.Method = WebRequestMethods.Http.Get;
            req.ContentType = "application/octet-stream";

            Console.WriteLine("wait for response");

            var rsp = req.GetResponse();

            if (rsp.ContentLength > 0)
            {
                var wfs = System.IO.File.Create("download.asset");
                var stream = rsp.GetResponseStream();
                var total = 0L;

                Console.WriteLine("start: {0}", rsp.ContentLength);

                while (total < rsp.ContentLength)
                {
                    var step = stream.Read(buf, 0, buf.Length);

                    if (step > 0)
                    {
                        total += step;
                        wfs.Write(buf, 0, step);

                        Console.WriteLine("read {0} bytes ({1})", total, 100f * (float)total / rsp.ContentLength);
                    }
                }

                Console.WriteLine("completed.");

                stream.Close();
                stream.Dispose();

                var hash = B2S(md5.ComputeHash(wfs));
                Console.WriteLine("hash: {0}", hash);
                if ("d41d8cd98f0b24e980998ecf8427e" != hash)
                {
                    Console.WriteLine("ERROR");
                }

                wfs.Close();
                wfs.Dispose();
            }
            else
            {
                Console.WriteLine("failed. {0} {1}", rsp.ContentType, rsp.ContentLength);
            }

            rsp.Close();
            rsp.Dispose();

            Console.WriteLine("end");
            Console.ReadKey(true);
        }
    }
}