Create and write Excel file in C# and VB.NET

using System.Drawing;
using GemBox.Spreadsheet;

class Program
{
    static void Main()
    {
        // If using Professional version, put your serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY");

        var workbook = new ExcelFile();
        ExcelWorksheet worksheet = workbook.Worksheets.Add("Writing");

        // Tabular sample data for writing into an Excel file.
        var skyscrapers = new object[21, 8]
        {
            { "Rank", "Building", "City", "Country", "Metric", "Imperial", "Floors", "Built (Year)" },
            { 1, "Burj Khalifa", "Dubai", "United Arab Emirates", 828, 2717, 163, 2010 },
            { 2, "Shanghai Tower", "Shanghai", "China", 632, 2073, 128, 2015 },
            { 3, "Abraj Al-Bait Clock Tower", "Mecca", "Saudi Arabia", 601, 1971, 120, 2012 },
            { 4, "Ping An Finance Centre", "Shenzhen", "China", 599, 1965, 115, 2017 },
            { 5, "Lotte World Tower", "Seoul", "South Korea", 554.5, 1819, 123, 2016 },
            { 6, "One World Trade Center", "New York City", "United States", 541.3, 1776, 104, 2014 },
            { 7, "Guangzhou CTF Finance Centre", "Guangzhou", "China", 530, 1739, 111, 2016 },
            { 7, "Tianjin CTF Finance Centre", "Tianjin", "China", 530, 1739, 98, 2018 },
            { 9, "China Zun", "Beijing", "China", 528, 1732, 108, 2018 },
            { 10, "Taipei 101", "Taipei", "Taiwan", 508, 1667, 101, 2004 },
            { 11, "Shanghai World Financial Center", "Shanghai", "China", 492, 1614, 101, 2008 },
            { 12, "International Commerce Centre", "Hong Kong", "China", 484, 1588, 118, 2010 },
            { 13, "Lakhta Center", "St. Petersburg", "Russia", 462, 1516, 86, 2018 },
            { 14, "Landmark 81", "Ho Chi Minh City", "Vietnam", 461.2, 1513, 81, 2018 },
            { 15, "Changsha IFS Tower T1", "Changsha", "China", 452.1, 1483, 88, 2017 },
            { 16, "Petronas Tower 1", "Kuala Lumpur", "Malaysia", 451.9, 1483, 88, 1998 },
            { 16, "Petronas Tower 2", "Kuala Lumpur", "Malaysia", 451.9, 1483, 88, 1998 },
            { 16, "The Exchange 106", "Kuala Lumpur", "Malaysia", 451.9, 1483, 97, 2018 },
            { 19, "Zifeng Tower", "Nanjing", "China", 450, 1476, 89, 2010 },
            { 19, "Suzhou IFS", "Suzhou", "China", 450, 1476, 92, 2017 }
        };

        worksheet.Cells["A1"].Value = "Example of writing typical table - tallest buildings in the world (2019):";

        // Column width of 8, 30, 16, 20, 9, 11, 9, 9, 4 and 5 characters.
        worksheet.Columns["A"].SetWidth(8, LengthUnit.ZeroCharacterWidth); // Rank
        worksheet.Columns["B"].SetWidth(30, LengthUnit.ZeroCharacterWidth); // Building
        worksheet.Columns["C"].SetWidth(16, LengthUnit.ZeroCharacterWidth); // City
        worksheet.Columns["D"].SetWidth(20, LengthUnit.ZeroCharacterWidth); // Country
        worksheet.Columns["E"].SetWidth(9, LengthUnit.ZeroCharacterWidth); // Metric
        worksheet.Columns["F"].SetWidth(11, LengthUnit.ZeroCharacterWidth); // Imperial
        worksheet.Columns["G"].SetWidth(9, LengthUnit.ZeroCharacterWidth); // Floors
        worksheet.Columns["H"].SetWidth(9, LengthUnit.ZeroCharacterWidth); // Built (Year)
        worksheet.Columns["I"].SetWidth(4, LengthUnit.ZeroCharacterWidth);
        worksheet.Columns["J"].SetWidth(5, LengthUnit.ZeroCharacterWidth);

        int i, j;
        // Write header data to Excel cells.
        for (j = 0; j < 8; j++)
            worksheet.Cells[3, j].Value = skyscrapers[0, j];

        worksheet.Cells.GetSubrange("A3:A4").Merged = true; // Rank
        worksheet.Cells.GetSubrange("B3:B4").Merged = true;  // Building
        worksheet.Cells.GetSubrange("C3:C4").Merged = true;  // City
        worksheet.Cells.GetSubrange("D3:D4").Merged = true;  // Country
        worksheet.Cells.GetSubrange("E3:F3").Merged = true; // Height
        worksheet.Cells["E3"].Value = "Height";
        worksheet.Cells.GetSubrange("G3:G4").Merged = true;  // Floors
        worksheet.Cells.GetSubrange("H3:H4").Merged = true;  // Built (Year)

        var style = new CellStyle();
        style.HorizontalAlignment = HorizontalAlignmentStyle.Center;
        style.VerticalAlignment = VerticalAlignmentStyle.Center;
        style.FillPattern.SetSolid(Color.Chocolate);
        style.Font.Weight = ExcelFont.BoldWeight;
        style.Font.Color = Color.White;
        style.WrapText = true;
        style.Borders.SetBorders(MultipleBorders.Right | MultipleBorders.Top, Color.Black, LineStyle.Thin);

        worksheet.Cells.GetSubrange("A3:H4").Style = style;

        style = new CellStyle();
        style.HorizontalAlignment = HorizontalAlignmentStyle.Center;
        style.VerticalAlignment = VerticalAlignmentStyle.Center;
        style.Font.Weight = ExcelFont.BoldWeight;

        var mergedRange = worksheet.Cells.GetSubrange("I5:I14");
        mergedRange.Merged = true;
        mergedRange.Value = "T o p   1 0";
        style.Rotation = -90;
        style.FillPattern.SetSolid(Color.Lime);
        mergedRange.Style = style;

        mergedRange = worksheet.Cells.GetSubrange("J5:J24");
        mergedRange.Merged = true;
        mergedRange.Value = "T o p   2 0";
        style.IsTextVertical = true;
        style.FillPattern.SetSolid(Color.Gold);
        mergedRange.Style = style;

        mergedRange = worksheet.Cells.GetSubrange("I15:I24");
        mergedRange.Merged = true;
        mergedRange.Style = style;

        // Write and format sample data to Excel cells.
        for (i = 0; i < 20; i++)
            for (j = 0; j < 8; j++)
            {
                var cell = worksheet.Cells[i + 4, j];

                cell.Value = skyscrapers[i + 1, j];

                if (i % 2 == 0)
                    cell.Style.FillPattern.SetSolid(Color.LightSkyBlue);
                else
                    cell.Style.FillPattern.SetSolid(Color.FromArgb(210, 210, 230));

                if (j == 4)
                    cell.Style.NumberFormat = "#\" m\"";

                if (j == 5)
                    cell.Style.NumberFormat = "#\" ft\"";

                if (j > 3)
                    cell.Style.Font.Name = "Courier New";

                cell.Style.Borders[IndividualBorder.Right].LineStyle = LineStyle.Thin;
            }

        worksheet.Cells.GetSubrange("A5", "J24").Style.Borders.SetBorders(MultipleBorders.Outside, Color.Black, LineStyle.Double);
        worksheet.Cells.GetSubrange("A3", "H4").Style.Borders.SetBorders(MultipleBorders.Vertical | MultipleBorders.Top, Color.Black, LineStyle.Double);
        worksheet.Cells.GetSubrange("A5", "I14").Style.Borders.SetBorders(MultipleBorders.Bottom | MultipleBorders.Right, Color.Black, LineStyle.Double);

        worksheet.Cells["A27"].Value = "Notes:";
        worksheet.Cells["A28"].Value = "a) \"Metric\" and \"Imperial\" columns use custom number formatting.";
        worksheet.Cells["A29"].Value = "b) All number columns use \"Courier New\" font for improved number readability.";
        worksheet.Cells["A30"].Value = "c) Multiple merged ranges were used for table header and categories header.";

        worksheet.PrintOptions.FitWorksheetWidthToPages = 1;

        workbook.Save("Writing.%OutputFileType%");
    }
}