输出服务器端文件到客户端

     string MIME = "application/vnd.ms-excel";
     Response.Clear();
     Response.AppendHeader("content-disposition", "attachment; filename="+ HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
     //设置输出文件类型
     Response.ContentType = MIME;
     //把文件流发送到客户端
     Response.WriteFile(filePath);
     Response.Flush();
     Response.Close();
     Response.End();