C# aspx 下载excel文件

public static void DownFile(string filePath, string fullName)
        {
            string path = HttpContext.Current.Server.MapPath(filePath);
            var file = new FileInfo(path);
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.Charset = "GB2312";
            HttpContext.Current.Response.ContentEncoding = Encoding.UTF8;
            // 添加头信息，为"文件下载/另存为"对话框指定默认文件名
            HttpContext.Current.Response.AddHeader("Content-Disposition",