private async Task <byte[]> GetPDF(byte[] file, string id)
        {
            byte[] ret = null;

            string baseUrl = _configuration["baseUrl"];

            string inputFilename = @"wwwroot/pdf-template/cert.html";

            string imgsrc = $"data:image/png;base64,{QR.GetPureBase64($"{baseUrl}/Contract/Certificate?id={id}")}";

            HtmlDto dto = new HtmlDto()
            {
                html = System.Web.HttpUtility.HtmlEncode(
                    Encoding.UTF8.GetString(
                        System.IO.File.ReadAllBytes(inputFilename)))
                       .Replace("{certificateid}", id)
                       .Replace("{qrlink}", imgsrc),

                footerPath = $"{baseUrl}/pdf-template/footer.html"
            };

            string jsonString = Newtonsoft.Json.JsonConvert.SerializeObject(dto);

            string uri = _configuration["pdfApi"];

            var content = new StringContent(jsonString, Encoding.UTF8, "application/json");

            var response = await client.PostAsync($"{uri}", content).ConfigureAwait(false);

            var file2 = await response.Content.ReadAsByteArrayAsync();

            ret = Concat.DoConcat(file, file2);

            return(ret);
        }
        public HttpResponseMessage GeneratePDF([FromBody] HtmlDto dto)
        {
            //string inputFilename = "cert-simple2.html";
            //string outputFilename = "cert-simple2.pdf";

            //string html = Encoding.UTF8.GetString(File.ReadAllBytes(inputFilename));

            //byte[] pdf = new SimplePechkin(new GlobalConfig()).Convert(html);

            //string htmlDecoded = HttpUtility.HtmlDecode(dto.html);



            var pdfBuilder = Pdf.From(HttpUtility.HtmlDecode(dto.html));


            //    pdfBuilder = pdfBuilder.WithObjectSetting("header.htmlUrl", dto.footerPath);

            if (!String.IsNullOrEmpty(dto.footerPath))
            {
                pdfBuilder = pdfBuilder.WithGlobalSetting("margin.top", "2cm")
                             .WithGlobalSetting("margin.bottom", "2cm")
                             //.WithObjectSetting("footer.center","THE FOOTER")
                             .WithObjectSetting("footer.htmlUrl", dto.footerPath);
            }

            var pdf = pdfBuilder.Content();

            //HttpContent content = new StreamContent();
            ByteArrayContent content = new ByteArrayContent(pdf);

            content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/pdf");
            content.Headers.Add("content-disposition", "attachment;filename=myFile.pdf");

            return(new HttpResponseMessage()
            {
                StatusCode = HttpStatusCode.OK,
                Content = content
            });
        }