HttpRequest获取文件流,HttpResponse输出文件流

            HttpResponse输出文件:
            Response.Clear();
            Response.ContentType = "application/octet-stream";
            //通知浏览器下载文件而不是打开
            Response.AddHeader("Content-Disposition", "attachment;   filename=aaa.csv"); 
             var sw = new StreamWriter(response.OutputStream);
            //cc.Write<CustomerData>(list, sw, csvFileDesc);
            sw.Flush();
            sw.Close();