ASP.NET download file from server

Question

I'd like to download a file from server to the client. Neither of the solutions I found across internet works, they all write the file to the server, but never pops the download window on the client's browser. I don't know whether it is a ASP.NET issue or IIS.

This is my code:

Workbook wb = getExcel();
string pathDownload = HttpContext.Current.Server.MapPath("~/Content/DOCUMENTS/temp/Excel.xls");

BIFF8Writer.WriteWorkbookToFile(wb, pathDownload);
byte[] fileContent = System.IO.File.ReadAllBytes(pathDownload);
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.ClearContent();

HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=Excel.xls");
HttpContext.Current.Response.BinaryWrite(fileContent);
HttpContext.Current.Response.Flush();
HttpContext.Current.Response.End();

Answer 1

Since WriteWorkbookToFile already writes the file in question to the file system, it is preferable to use it straight from there rather than load it into memory and then do a BinaryWrite.

remove the line:

byte[] fileContent = System.IO.File.ReadAllBytes(pathDownload);

and then replace the line:

HttpContext.Current.Response.BinaryWrite(fileContent);

with:

HttpContext.Current.Response.TransmitFile(pathDownload);