下载文件方法

 第二个参数为要下载的文件的地址，第三个参数为文件名称。

    public void DownloadFile(HttpResponse response, string serverPath,string fileName)    {        FileStream fs = null;        try        {            fs = File.OpenRead(serverPath);            byte[] buffer = new byte[1024];            long count = 1024;            response.Buffer = true;            response.AddHeader("Connection", "Keep-Alive");            response.ContentType = "application/octet-stream";            response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fileName));//下载时要保存的默认文件名             response.AddHeader("Content-Length", fs.Length.ToString());            while (count == 1024)            {                count = fs.Read(buffer, 0, 1024);                response.BinaryWrite(buffer);            }            response.End();        }        finally        {            fs.Close();        }    }