把实际地址写入cs文件中，不要暴露在外，或者加密url

代码

   
     

    
      
    
      //
    
      download.aspx.cs
    
      

    
      protected
    
       
    
      void
    
       Page_Load(
    
      object
    
       sender, EventArgs e)
 {
 String fileUrl 
    
      =
    
       Request.QueryString[
    
      "
    
      file
    
      "
    
      ].Trim().Replace(
    
      "
    
      ~
    
      "
    
      , 
    
      ""
    
      ); 
 
    
      string
    
       DownloadFileName 
    
      =
    
       Server.MapPath(
    
      "
    
      ~
    
      "
    
      ) 
    
      +
    
       fileUrl;
 
    
      string
    
       filepath 
    
      =
    
       DownloadFileName;
 
    
      string
    
       filename 
    
      =
    
       System.IO.Path.GetFileName(filepath);
 Response.Clear();
 Response.ContentType 
    
      =
    
       
    
      "
    
      application/octet-stream
    
      "
    
      ;
 Response.AddHeader(
    
      "
    
      Content-Disposition
    
      "
    
      , 
    
      "
    
      attachment; filename=
    
      "
    
       
    
      +
    
       filename);
 Response.Flush();
 Response.WriteFile(filepath);
 }