Download file in directory

 ArrayList FoldersFiles = new ArrayList();
            string strFolder = Server.MapPath("~/Etickets/");        //"C:\\Etickets\\";
            DirectoryInfo folder = new DirectoryInfo(strFolder);

            if (folder.Exists)
            {
                string[] Folder;
                Folder = Directory.GetDirectories(strFolder);
                foreach (string FolderName in Folder)
                {
                    FileInfo fi = new FileInfo(FolderName);
                    FoldersFiles.Add(fi.Name);
                    if (e.CommandArgument.ToString() == fi.Name)
                    {

                        string[] files;

                        string path = strFolder;
                        path += e.CommandArgument.ToString();
                        DirectoryInfo di = new DirectoryInfo(path);
                         FileInfo[] rgFiles = di.GetFiles("*.pdf");
                    
                         foreach (FileInfo fileName in rgFiles)
                        {
                  

                            Response.ContentType = "Application/pdf";

                            Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName);
                            Response.TransmitFile(path +"\\"+ fileName);
                       
                            Response.End();
                        }
                            
                   

                    }
            
                }

            }

        }