Download file using c#

string filename="Connectivity.doc";

if (filename != "")

{

          string path = Server.MapPath(filename);

          System.IO.FileInfo file = new System.IO.FileInfo(path);

          if (file.Exists)

          {

                   Response.Clear();

                   Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);

                   Response.AddHeader("Content-Length", file.Length.ToString());

                   Response.ContentType = "application/octet-stream";

                   Response.WriteFile(file.FullName);

                   Response.End();

          }

          else

          {

                   Response.Write("This file does not exist.");

          }

}



(OR)

// The file path to download.

        string filepath = @"C:\filename.extention";

        // The file name used to save the file to the client's system..

        string filename = Path.GetFileName(filepath);

        System.IO.Stream stream = null;

        try

        {

            // Open the file into a stream.

            stream = new FileStream(filepath, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read);

            // Total bytes to read:

            long bytesToRead = stream.Length;

            Response.ContentType = "application/octet-stream";

            Response.AddHeader("Content-Disposition", "attachment; filename=" + filename);

            // Read the bytes from the stream in small portions.

            while (bytesToRead > 0)

            {

                // Make sure the client is still connected.

                if (Response.IsClientConnected)

                {

                    // Read the data into the buffer and write into the

                    // output stream.

                    byte[] buffer = new Byte[10000];

                    int length = stream.Read(buffer, 0, 10000);

                    Response.OutputStream.Write(buffer, 0, length);

                    Response.Flush();

                    // We have already read some bytes.. need to read

                    // only the remaining.

                    bytesToRead = bytesToRead - length;

                }

                else

                {

                    // Get out of the loop, if user is not connected anymore..

                    bytesToRead = -1;

                }

            }

        }

        catch (Exception ex)

        {

            Response.Write(ex.Message);

            // An error occurred..

        }

        finally

        {

            if (stream != null)

            {

                stream.Close();

            }

        }