我写的下载文件代码怎么没有后缀名啊..
public ActionResult DownLoad() {

  int id =Convert.ToInt32(Session["id"]);
  Article article = resourceMangerServices.GetArticleById(id);
  string directory = Server.MapPath("/FileUpdate");
  string FilePath = directory + article.Attachment;
  System.IO.FileInfo DownloadFile = new System.IO.FileInfo(FilePath);
  Response.Clear();
  Response.ContentType = "application/octet-stream ";
  Response.AppendHeader("Content-Disposition ", "attachment;filename=" + HttpUtility.UrlEncode(DownloadFile.FullName, System.Text.Encoding.UTF8));
  Response.AppendHeader("Content-Length", DownloadFile.Length.ToString());
  Response.WriteFile(DownloadFile.FullName);
  Response.Flush();
  Response.End();
  return new EmptyResult();
   
  } 高手 求解

------解决方案--------------------
定义个处理程序

<a href="/DownloadHandler.ashx?filename=111111">点击下载</a>



public class DownloadHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
HttpRequest Request = HttpContext.Current.Request;
HttpResponse Response = HttpContext.Current.Response;
string strDirectory = HttpContext.Current.Server.MapPath("~");

string strFilePath = strDirectory + context.Request.QueryString["filename"]; //真实文件地址
 System.IO.FileInfo DownloadFile = new System.IO.FileInfo(strFilePath );
string strFileName = DownloadFile.Name; 
byte[] datas = System.IO.File.ReadAllBytes(strFilePath);
Response.AddHeader("Content-Disposition", "attachment;filename= \"" + HttpUtility.UrlEncode(strFileName) + "\";");
Response.AddHeader("Content-Type", "text/html"); // 需修改
Response.OutputStream.Write(datas, 0, datas.Length);
}

public bool IsReusable
{
get
{
return false;
}
}
}

------解决方案--------------------

C# code

using System;
using System.Collections;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;

namespace Asiastar.NR.Ajax
{
    /// <summary>
    /// $codebehindclassname$ 的摘要说明
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class Handler1 : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";

            string id = context.Request["id"].ToString();//获取资源的编号
            System.IO.Stream iStream = null;
            byte[] buffer = new Byte[10000];
            int length;
            long dataToRead;
            NRBLL.File bf = new Asiastar.NRBLL.File();
            Guid guid = new Guid(id);
            if (bf.FN_SerchPathByFileId(guid).Tables[0].Rows[0]["FilePath"] != null)//判断数据库路径是否存在         
            {
                string filepath = bf.FN_SerchPathByFileId(guid).Tables[0].Rows[0]["FilePath"].ToString();//获取资源完整路径                   D:\资源文件\600cc139-14cf-448e-9e50-daa972d35e01.jpg
                string Oidfilename = bf.FN_SerchPathByFileI