HTTP文件下载

                FileInfo fi = new FileInfo(FilePath);                HttpResponse contextResponse = System.Web.HttpContext.Current.Response;                contextResponse.Clear();                contextResponse.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode("FileName", System.Text.Encoding.UTF8));                contextResponse.AddHeader("Content-Length",fi.Length.ToString());                contextResponse.ContentType = "application/octet-stream";                contextResponse.Filter.Close();                contextResponse.WriteFile(fi.FullName);                contextResponse.End();                contextResponse.Flush();