How to download file with asp.net on buttton's onClick event?

Question

I have a String variable (in C#) that contain the full path of PDF file on my server (like that \"~/doc/help.pdf\").

I want that in click on button, this file will down

Answer 1

Response.ContentType = "Application/pdf";

Response.AppendHeader("Content-Disposition", "attachment; filename=File_Name.pdf");

Response.TransmitFile(Server.MapPath("Folder_Name/File_Name.pdf"));

Response.End();