C#隐藏文件下载路径的方法

关于下载路径的隐藏都是通过传递一个数据库中的ID，然后在另外一张页面通过传递的ID在数据库中读出路径。
c#中实现的方法（只需要.ASPX.CS的代码就可以了）


string sel_sql="select FileVisualPath from TabMailAttachFiles where FileID="+Request.QueryString["destFileName"].ToString();




// string destFileName = Request.QueryString["destFileName"]!=null?Request.QueryString["destFileName"]:"";


string destFileName=ROA.Components.fune_commerce.Execad(sel_sql).Tables[0].Rows[0][0].ToString();


destFileName = Server.MapPath(".")+destFileName;


destFileName = Server.UrlDecode(destFileName);


if(File.Exists(destFileName))






{


FileInfo fi = new FileInfo(destFileName);


Response.Clear();


Response.ClearHeaders();


Response.Buffer = false;




//Response.AppendHeader("Content-Disposition","attachment;filename=" +HttpUtility.UrlEncode(Path.GetFileName(destFileName),System.Text.Encoding.Default));


Response.AppendHeader("Content-Disposition","attachment;filename=" +HttpUtility.UrlEncode(Path.GetFileName(destFileName),System.Text.Encoding.UTF8));


Response.AppendHeader("Content-Length",fi.Length.ToString());


Response.ContentType="application/octet-stream";


Response.WriteFile(destFileName);


Response.Flush();


Response.End();


}


else






{


Response.Write("<script langauge=javascript>alert('文件不存在!');history.go(-1);</script>");


Response.End();


}