public IActionResult ViewHistoryRequest() { Lightning lnd = GetLightning(); Google.Protobuf.ByteString RHash; string invoiceString; Bitmap qrCode; int satoshis = 100; string memo = "View History"; (invoiceString, qrCode, RHash) = lnd.GetInvoice((long)Convert.ToDouble(satoshis), memo); string filename = invoiceString.Substring(0, 20) + ".jpg"; string outputFileName = Path.Combine(_myData.BillsPath, filename); HttpContext.Session.Set("QRFilenameHistory", Encoding.ASCII.GetBytes(outputFileName)); using (MemoryStream memory = new MemoryStream()) { using (FileStream fs = new FileStream(outputFileName, FileMode.Create, FileAccess.ReadWrite)) { qrCode.Save(memory, ImageFormat.Jpeg); byte[] bytes = memory.ToArray(); fs.Write(bytes, 0, bytes.Length); } } byte[] hasharray = RHash.ToByteArray(); HttpContext.Session.Set("HashHistory", hasharray); return(new JsonResult(new { billFilename = filename, billText = invoiceString })); }