.net下 如何实现安全下载功能？（隐藏真实的下载地址）

Question

 问题描述： 现在在我的库里存储了 一个网络上一个绝对地址：
    如：http://test.test.com/reports/2010-8-18_73724a26-cf92-49c5-b25c-53a792d29231.pdf    隐藏真实的下载地址，实现安全下载功能！  
    像 CSDN 的下载功能那样： http://d.download.csdn.net/down/2795717/niuxuexin 求解决方案~~~~~~~~~~！！！！！

Answer 1

Response.WriteFile("../Files/yourfname");

Answer 2

 public static void DownloadXLSFile(FileInfo file, Control ctr, string fileName)
        {
            var response = ctr.Page.Response;            response.AddHeader("Content-Disposition", string.Format("attachment;filename={0}", fileName));
            response.Charset = "UTF-8";
             response.ContentType = "application/octet-stream";            var stream = new System.IO.FileStream(file.FullName, FileMode.Open, FileAccess.Read);
            try
            {
                while (true)
                {
                    byte[] buffer = new byte[1024];
                    int leng = stream.Read(buffer, 0, 1024);
                    if (leng == 0)
                        break;
                    if (leng == 1024)
                    {
                        response.BinaryWrite(buffer);
                    }
                    else
                    {
                        byte[] b = new byte[leng];
                        for (int i = 0; i < leng; i++)
                        {
                            b[i] = buffer[i];
                        }
                        response.BinaryWrite(b);
                    }
                }
            }
            finally
            {
                stream.Close();
            }        }

Answer 3

/// <summary>
        /// 以指定的ContentType输出指定文件文件
        /// </summary>
        public static void ResponseFile(string filepath, string filename, string filetype)
        {
            Stream iStream = null;            // 缓冲区为10k
            byte[] buffer = new Byte[10000];
            // 文件长度
            int length;
            // 需要读的数据长度
            long dataToRead;            try
            {
                // 打开文件
                iStream = new FileStream(filepath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);                // 需要读的数据长度
                dataToRead = iStream.Length;                HttpContext.Current.Response.ContentType = filetype;
                HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + Utils.UrlEncode(filename.Trim()));                while (dataToRead > 0)
                {
                    // 检查客户端是否还处于连接状态
                    if (HttpContext.Current.Response.IsClientConnected)
                    {
                        length = iStream.Read(buffer, 0, 10000);
                        HttpContext.Current.Response.OutputStream.Write(buffer, 0, length);
                        HttpContext.Current.Response.Flush();
                        buffer = new Byte[10000];
                        dataToRead = dataToRead - length;
                    }
                    else
                    {
                        // 如果不再连接则跳出死循环
                        dataToRead = -1;
                    }
                }
            }
            catch (Exception ex)
            {
                HttpContext.Current.Response.Write("Error : " + ex.Message);
            }
            finally
            {
                if (iStream != null)
                {
                    // 关闭文件
                    iStream.Close();
                }
            }
            HttpContext.Current.Response.End();
        }