FileInfo fi = new FileInfo(Server.MapPath(Request.ApplicationPath.ToString()+"\\MyDoc\\"+FileName));
Response.Clear();  
Response.ClearHeaders(); 
Response.Buffer = false;
Response.ContentType = "application/octet-stream" ;   
Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fi.FullName, System.Text.Encoding.UTF8));
Response.AppendHeader("Content-Length", fi.Length.ToString()) ;
Response.WriteFile(fi.FullName); 
Response.Flush();  
Response.Close();  如果我直接打开这个文件是页面仍然可以提交,如果我保存到本地页面就不能提交了