asp.net 獲取服務器指定文件夾目錄文件，并提供下載

 string dirPath = HttpContext.Current.Server.MapPath("uploads/");            if (Directory.Exists(dirPath))            {                //獲得目錄信息                DirectoryInfo dir = new DirectoryInfo(dirPath);                //獲得目錄文件列表                FileInfo[] files = dir.GetFiles("*.*");                string[] fileNames = new string[files.Length];                //臨時數據表                DataTable dt = new DataTable();                dt.Columns.Add("FileName");                               foreach (FileInfo fileInfo in files)                {                    DataRow dr = dt.NewRow();                    dr["FileName"] = fileInfo.Name;                    dt.Rows.Add(dr);                }                Repeater1.DataSource = dt;                Repeater1.DataBind();            }

if (e.CommandName == "down")        {                      try            {                    string DownloadFileName = "~/uploads/" + e.CommandArgument.ToString();//文件路徑                    string filepath = Server.MapPath(DownloadFileName);                    string filename = Path.GetFileName(filepath);                    FileInfo file = new FileInfo(filepath);                    Response.Clear();                    Response.ContentType = "application/octet-stream";                    Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8));                    Response.AddHeader("Content-length", file.Length.ToString());                    Response.Flush();                    Response.WriteFile(filepath);            }            catch            {                Response.Write("<scr