: try ...{ FullFileName = Server.MapPath(FileName); //FileName--要下載的文件名 FileInfo DownloadFile= new FileInfo(FullFileName); if(DownloadFile.Exists) ...{ Response.Clear(); Response.ClearHeaders(); Response.Buffer=false; Response.ContentType="application/octet-stream"; Response.AppendHeader("Content-Disposition","attachment;filename=" +HttpUtility.UrlEn買粉絲de(DownloadFile.FullName,System.Text.En買粉絲ding.ASCII)); Response.AppendHeader("Content-Length",DownloadFile.Length.ToString()); Response.WriteFile(DownloadFile.FullName); Response.Flush(); Response.End(); } else ...{ //文件不存在 } } catch ...{ //文件不存在 }