Performance issue when have style section in html

hi,
I’m using convert html to excel, and notice css style will slow performance very much, is there any solution or suggestion for that?
it spent about 35 seconds to complete work, if i remove css style, it’s will reduce to 8 seconds

my code:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Excel = GemBox.Spreadsheet;


namespace GemboxPerformanceTest
{
    internal class Program
    {
        static void Main(string[] args)
        {
            BuildExcelWithHTML();
        }

        private static void BuildExcelWithHTML()
        {

            
            Excel.SpreadsheetInfo.SetLicense("dfdfdf==A");
            var htmlOptions = new Excel.HtmlLoadOptions();
            htmlOptions.DateTimeFormats.Insert(0, "MM/dd/yyyy");
            var html = GenerateHTML();
            var htmlStream = new MemoryStream(htmlOptions.Encoding.GetBytes(html));

            Stopwatch stopWatch = new Stopwatch();
            stopWatch.Start();
            var workbook = Excel.ExcelFile.Load(htmlStream, htmlOptions);
            var xlsxStream = new MemoryStream();
            workbook.Save("test.xlsx", Excel.SaveOptions.XlsxDefault);
            stopWatch.Stop();
            // Get the elapsed time as a TimeSpan value.
            TimeSpan ts = stopWatch.Elapsed;

            // Format and display the TimeSpan value.
            string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
                ts.Hours, ts.Minutes, ts.Seconds,
                ts.Milliseconds / 10);
            Console.WriteLine("RunTime " + elapsedTime);
        }

        private static string GenerateHTML()
        {
            var template = @"<html>
			<head>
			<style>
			@page { 
				margin: 0.5cm;

			}
            table, th, td {
                border: 1px solid black;
                border-collapse: collapse;
            }
            th, td {
                padding: 15px;
                font-family:""Calibri, sans-serif"";

            }
            </style>
			</head>
			<body>
			    {{content}}
			</body>
			</html>";
            var result = new StringBuilder();
            var columns = new List<dynamic>
            {
                new { Name = "Date", Width = "100" },
                new { Name = "Name", Width = "200" },
                new { Name = "User", Width = "150" },
                new { Name = "Tag", Width = "100" },
                new { Name = "Entry", Width = "100" },
                new { Name = "Remarks", Width = "300" },
                new { Name = "c", Width = "100" },
                new { Name = "b", Width = "100" },
            };
            result.Append("<table><thead><tr>");
            foreach (var column in columns)
            {
                result.AppendFormat("<th width='{1}px'>{0}</th>", column.Name, column.Width);
            }
            result.Append("</tr></thead>");
            result.Append("</tbody>");

            for (var i = 0; i < 20000; i++)
            {
                result.Append("<tr>");
                foreach (var column in columns)
                {
                    var value = column.Name + i;
//                    if (column.Name == "Remarks")
//                    {
//                        value = @"HSE Incidents: No Current Activity @ dfdf: RELEASED TO RIO PECOS 27-18 SL UNIT 1 # 251 Depth @ dfdfdf: 1,318’ MD MW @ dfdf:  Last Survey: (1,263’ MD, 3.21° INC, 295.10° AZI, 1,262.01’ TVD, 19.05’ VS, 9.41 +N/-S:, -39.53 +E/-W:, 0.81° DLS)          Distance Above/Below & Left/Right of target plan/line: 6’ AHEAD & 3’ LEFT 24 Hr Summary: DRILL F/ 698' TO TD @ 1,dfdf'. CUC, PUMP SWEEPS, SPOT PILL, TOOH FOR CASING & CEMENT OPERATIONS. LAND CASING @ 1,303'. CIRC & COND. RD FRANKS, REMOVE LANDING JOINT AND RELEASE RIG TO RIO PECOS 27-18 SL UNIT 1 #251 @ 1400hRS Cumulative NPT for well: 1 HRS Daily Cost/Cumulative Cost: $134,698 / $218,407 
//" + i;
//                    }
//                    else if (column.Name == "Date")f
//                    {
//                        value = DateTime.Now.AddMinutes(-i).ToString("MM/dd/yyyy hh:mm tt");
//                    }
                    result.AppendFormat("<td>{0}</td>", value);
                }
                result.Append("</tr>");
            }
            result.Append("</tbody></table>");
            return template.Replace("{{content}}", result.ToString());
        }
    }
}

Hi Chandler!

We will profile GemBox.Spreadsheet using your scenario (with and without the ‘style’ tag) to see if there are any bottlenecks.

We will inform you when we finish (probably in the first half of the next week).

Regards,
Stipo

Thanks, please also help to check the performance for PDF if possbile, same, html content, pdf took 40S to finished with out Css style, and spent 1 min to finish with css style

      private static void BuildPDFWithHTML()
        {
            var html = GenerateHTML();
            Stopwatch stopWatch = new Stopwatch();
            stopWatch.Start();
            var options = new HtmlLoadOptions();
            ComponentInfo.SetLicense("==A");

            using (var stream = new MemoryStream(options.Encoding.GetBytes(html)))
            {
                // Load input HTML text as stream.
                var document = DocumentModel.Load(stream, options);
                // Save output PDF file.
                document.Save("test.pdf", SaveOptions.PdfDefault);

            }
            // Get the elapsed time as a TimeSpan value.
            TimeSpan ts = stopWatch.Elapsed;

            // Format and display the TimeSpan value.
            string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
                ts.Hours, ts.Minutes, ts.Seconds,
                ts.Milliseconds / 10);
            Console.WriteLine("RunTime " + elapsedTime);
        }

Hi Chandler,

Please try again with this bugfix:
https://www.gemboxsoftware.com/spreadsheet/nightlybuilds/GBS49v1082.zip

Or this NuGet package:
Install-Package GemBox.Spreadsheet -Version 49.0.1082-hotfix

Does this solve your issue?

Regards,
Mario

Yes, performance has been improved very much!
thanks