C#文件上传与下载的实现方法

publicActionResult Upload()
   {
     // var pathUrl = "http://" + Request.Url.Authority;
     var file = Request.Files["Filedata"];
 
     var uploadFileName = file.FileName;
 
     stringfilePath ="/File/"+ uploadFileName;
     stringAbsolutePath = Server.MapPath(filePath);
     file.SaveAs(AbsolutePath);      //将上传的东西保存    
     returnJson(new{ FileName = uploadFileName, FilePath = filePath });
 
   }

publicActionResult DownLoad(stringFileName)
   {
     stringfileName = FileName;//客户端保存的文件名
     stringfilePath = Server.MapPath("/File/"+ FileName);//路径   
                                //以字符流的形式下载文件  
     FileStream fs =newFileStream(filePath, FileMode.Open);
     byte[] bytes =newbyte[(int)fs.Length];
     fs.Read(bytes, 0, bytes.Length);
     fs.Close();
     Response.ContentType ="application/octet-stream";
 
     //通知浏览器下载文件而不是打开 
     Response.AddHeader("Content-Disposition","attachment; filename="+ HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
     Response.BinaryWrite(bytes);
     Response.Flush();
     Response.End();
     returnJson("");
   }