C#

WebClient wc = new WebClient();
wc.DownloadFile(@"http://aaa.uuu", @"D:\111.gig");

// Get the physical Path of the file(test.doc)
   string filepath = Server.MapPath("test.doc");
   // Create New instance of FileInfo class to get the properties of the file being downloaded
   FileInfo file = new FileInfo(filepath);
   // Checking if file exists
   if (file.Exists)
   {
    // Clear the content of the response
    Response.ClearContent();
    // LINE1: Add the file name and attachment, which will force the open/cance/save dialog to show, to the header
    Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);
    // Add the file size into the response header
    Response.AddHeader("Content-Length", file.Length.ToString());
    // Set the ContentType. function "ReturnExtension" return the proper content type and set it to the Response.ContentType property (not in this listing)
    Response.ContentType = ReturnExtension(file.Extension.ToLower());
    // Write the file into the response (TransmitFile is for ASP.NET 2.0. In ASP.NET 1.1 you have to use WriteFile instead)
    Response.TransmitFile(file.FullName);
    // End the response
    Response.End();
   }

class Program
    {
        static SerialPort sp = new SerialPort("COM8", 56000, Parity.None, 8);

        static void Main(string[] args)
        {
            if(!sp.IsOpen)
                sp.Open();
            sp.WriteLine("AT+DS44=?");
            sp.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);

            ThreadStart ts = new ThreadStart(f);
            Thread t = new Thread(ts);
            t.Start();
        }

        static void f()
        {
            while (true) ;
        }

        static void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            Console.WriteLine("DataRecieved..............................");
            string str = sp.ReadLine();
            Console.WriteLine(str + "......................................");
        }
    }