Excel spreadsheet library for C#/VB.NET

ExpertXls Excel Spreadsheet Library for .NET

Create Excel Spreadsheets in ASP.NET / C#

Add Formulas to an Excel Worksheet Using ExpertXls Excel Library for .NET

This sample shows how to add formulas to a worksheet. The library also offers an integrated formula calculation engine which allows you to calculate the formula results and set the result in the workbook.
To create the Excel workbook first select the format of the generated workbook and press the Create Workbook button. The Excel workbook will be created on the server and sent as an attachment to the browser. You will be prompted to open the generated workbook in an external viewer. ExpertXls library can generate both XLS and XLSX files.
Workbook Format:
Create Workbook Button Create Excel Workbook
Source Code:

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.Drawing;
using ExpertXls.ExcelLib;

public partial class FormulasDemo : System.Web.UI.Page
    protected void Page_Load(object sender, EventArgs e)

    protected void lnkBtnCreateWorkbook_Click(object sender, EventArgs e)
        // get the Excel workbook format
        ExcelWorkbookFormat workbookFormat = radioXlsFormat.Checked ? ExcelWorkbookFormat.Xls_2003 : ExcelWorkbookFormat.Xlsx_2007;

        // create the workbook in the desired format with a single worksheet
        ExcelWorkbook workbook = new ExcelWorkbook(workbookFormat);

        // set the license key before saving the workbook
        //workbook.LicenseKey = "your license key here";

        // set workbook description properties
        workbook.DocumentProperties.Subject = "Formulas demo";
        workbook.DocumentProperties.Comments = "Add formulas to an Excel worksheet using ExpertXls Excel library for .NET";


        #region Add a style used for the cells in the worksheet title area

        ExcelCellStyle titleStyle = workbook.Styles.AddStyle("WorksheetTitleStyle");
        // center the text in the title area
        titleStyle.Alignment.HorizontalAlignment = ExcelCellHorizontalAlignmentType.Center;
        titleStyle.Alignment.VerticalAlignment = ExcelCellVerticalAlignmentType.Center;
        // set the title area borders
        titleStyle.Borders[ExcelCellBorderIndex.Bottom].Color = Color.Green;
        titleStyle.Borders[ExcelCellBorderIndex.Bottom].LineStyle = ExcelCellLineStyle.Medium;
        titleStyle.Borders[ExcelCellBorderIndex.Top].Color = Color.Green;
        titleStyle.Borders[ExcelCellBorderIndex.Top].LineStyle = ExcelCellLineStyle.Medium;
        titleStyle.Borders[ExcelCellBorderIndex.Left].Color = Color.Green;
        titleStyle.Borders[ExcelCellBorderIndex.Left].LineStyle = ExcelCellLineStyle.Medium;
        titleStyle.Borders[ExcelCellBorderIndex.Right].Color = Color.Green;
        titleStyle.Borders[ExcelCellBorderIndex.Right].LineStyle = ExcelCellLineStyle.Medium;
        if (workbookFormat == ExcelWorkbookFormat.Xls_2003)
            // set the solid fill for the title area range with a custom color
            titleStyle.Fill.FillType = ExcelCellFillType.SolidFill;
            titleStyle.Fill.SolidFillOptions.BackColor = Color.FromArgb(255, 255, 204);
            // set the gradient fill for the title area range with a custom color
            titleStyle.Fill.FillType = ExcelCellFillType.GradientFill;
            titleStyle.Fill.GradientFillOptions.Color1 = Color.FromArgb(255, 255, 204);
            titleStyle.Fill.GradientFillOptions.Color2 = Color.White;
        // set the title area font 
        titleStyle.Font.Size = 14;
        titleStyle.Font.Bold = true;
        titleStyle.Font.UnderlineType = ExcelCellUnderlineType.Single;


        #region Add a style used for text messages

        ExcelCellStyle textMessageStyle = workbook.Styles.AddStyle("TextMessageStyle");
        textMessageStyle.Font.Size = 12;
        textMessageStyle.Font.Bold = true;
        textMessageStyle.Alignment.VerticalAlignment = ExcelCellVerticalAlignmentType.Center;
        textMessageStyle.Alignment.HorizontalAlignment = ExcelCellHorizontalAlignmentType.Left;
        textMessageStyle.Fill.FillType = ExcelCellFillType.SolidFill;
        textMessageStyle.Fill.SolidFillOptions.BackColor = Color.LightBlue;
        textMessageStyle.Borders[ExcelCellBorderIndex.Bottom].LineStyle = ExcelCellLineStyle.Thin;
        textMessageStyle.Borders[ExcelCellBorderIndex.Top].LineStyle = ExcelCellLineStyle.Thin;
        textMessageStyle.Borders[ExcelCellBorderIndex.Left].LineStyle = ExcelCellLineStyle.Thin;
        textMessageStyle.Borders[ExcelCellBorderIndex.Right].LineStyle = ExcelCellLineStyle.Thin;


        #region Add a style used for the formula results

        ExcelCellStyle formulaResultStyle = workbook.Styles.AddStyle("FormulaResultStyle");
        formulaResultStyle.Font.Size = 10;
        formulaResultStyle.Font.Bold = true;
        formulaResultStyle.Alignment.VerticalAlignment = ExcelCellVerticalAlignmentType.Center;
        formulaResultStyle.Fill.FillType = ExcelCellFillType.SolidFill;
        formulaResultStyle.Fill.SolidFillOptions.BackColor = Color.FromArgb(204, 255, 204);
        formulaResultStyle.Borders[ExcelCellBorderIndex.Bottom].LineStyle = ExcelCellLineStyle.Thin;
        formulaResultStyle.Borders[ExcelCellBorderIndex.Top].LineStyle = ExcelCellLineStyle.Thin;
        formulaResultStyle.Borders[ExcelCellBorderIndex.Left].LineStyle = ExcelCellLineStyle.Thin;
        formulaResultStyle.Borders[ExcelCellBorderIndex.Right].LineStyle = ExcelCellLineStyle.Thin;



        // get the first worksheet in the workbook
        ExcelWorksheet worksheet = workbook.Worksheets[0];

        // set the default worksheet name
        worksheet.Name = "Formulas Demo";

        #region WORKSHEET PAGE SETUP

        // set worksheet paper size and orientation, margins, header and footer
        worksheet.PageSetup.PaperSize = ExcelPagePaperSize.PaperA4;
        worksheet.PageSetup.Orientation = ExcelPageOrientation.Portrait;
        worksheet.PageSetup.LeftMargin = 1;
        worksheet.PageSetup.RightMargin = 1;
        worksheet.PageSetup.TopMargin = 1;
        worksheet.PageSetup.BottomMargin = 1;

        // add header and footer

        //display a logo image in the left part of the header
        string imagesPath = System.IO.Path.Combine(Server.MapPath("~"), @"Images");
        System.Drawing.Image logoImg = System.Drawing.Image.FromFile(System.IO.Path.Combine(imagesPath, "logo.jpg"));
        worksheet.PageSetup.LeftHeaderFormat = "&G";
        worksheet.PageSetup.LeftHeaderPicture = logoImg;
        // display worksheet name in the right part of the header
        worksheet.PageSetup.RightHeaderFormat = "&A";

        // add worksheet header and footer
        // display the page number in the center part of the footer
        worksheet.PageSetup.CenterFooterFormat = "&P";
        // display the workbook file name in the left part of the footer
        worksheet.PageSetup.LeftFooterFormat = "&F";
        // display the current date in the right part of the footer
        worksheet.PageSetup.RightFooterFormat = "&D";



        // merge the cells in the range to create the title area 
        // gets the merged range containing the top left cell of the range
        ExcelRange titleRange = worksheet["A2"].MergeArea;
        // set the text of title area
        worksheet["A2"].Text = "Adding Formulas to an Excel Worksheet";

        // set a row height of 18 points for each row in the range
        titleRange.RowHeightInPoints = 18;
        // set the worksheet top title style
        titleRange.Style = titleStyle;


        // set first column width
        worksheet["A1"].ColumnWidthInChars = 37;

        // Note: 
        // Set the properties below before assigning any formula or array formula to a cell
        // The properties below are used when parsing the formula assigned to a cell or a range of cells
        workbook.FormulaParamsSeparator = ',';
        workbook.FormulaRowsSeparator = ';';
        workbook.FormulaNumberFormat = System.Globalization.NumberFormatInfo.InvariantInfo;

        worksheet["A5:G5"].Style = textMessageStyle;
        worksheet["A5:G5"].Value = "Ordinary Formulas:";

        worksheet["A7"].Value = "FORMULA DATA:";
        worksheet["A7"].Style.Font.Bold = true;

        worksheet["C7"].Value = 100.5;
        worksheet["D7"].Value = 50.5;
        worksheet["E7"].Value = 89;
        worksheet["F7"].Value = 15.75;
        worksheet["G7"].Value = 44.25;

        worksheet["A9"].Value = "SUM(C7:G7)";
        worksheet["A9"].Style.Font.Color = Color.DarkBlue;
        worksheet["A9"].AddComment("Calculate the sum of the numbers in the range C7:G7");
        // add formula
        worksheet["C9"].Formula = "=SUM(C7:G7)";
        worksheet["C9"].Style = formulaResultStyle;

        worksheet["A11"].Value = "AVERAGE(C7:G7)";
        worksheet["A11"].Style.Font.Color = Color.DarkBlue;
        worksheet["A11"].AddComment("Calculate the average of the numbers in the range C7:G7");
        // add formula
        worksheet["C11"].Formula = "=AVERAGE(C7:G7)";
        worksheet["C11"].Style = formulaResultStyle;

        worksheet["A13"].Value = "MIN(C7:G7)";
        worksheet["A13"].Style.Font.Color = Color.DarkBlue;
        worksheet["A13"].AddComment("Calculate the mimimum value in the range C7:G7");
        // add formula
        worksheet["C13"].Formula = "=MIN(C7:G7)";
        worksheet["C13"].Style = formulaResultStyle;

        worksheet["A15"].Value = "C7 + 100.45";
        worksheet["A15"].Style.Font.Color = Color.DarkBlue;
        worksheet["A15"].AddComment("Add a constant to the value from C7");
        // add formula
        worksheet["C15"].Formula = "=C7 + 100.45";
        worksheet["C15"].Style = formulaResultStyle;

        worksheet["A17"].Value = "IF(C7>E7, C7, E7)";
        worksheet["A17"].Style.Font.Color = Color.DarkBlue;
        worksheet["A17"].AddComment("Calculate maximum between C7 and D7 using the IF function");
        // add formula
        worksheet["C17"].Formula = "=IF(C7>E7, E7, E7)";
        worksheet["C17"].Style = formulaResultStyle;

        worksheet["A20:G20"].Style = textMessageStyle;
        worksheet["A20:G20"].Value = "Array Formulas:";

        worksheet["A22"].Value = "FORMULA DATA:";
        worksheet["A22"].Style.Font.Bold = true;
        worksheet["A22"].AddComment("Intialized with an array formula");

        // use an array formula to initialize the test data
        // it is equivalent with the commented code below
        worksheet["C22:G22"].FormulaArray = "{10, -5, 2, 21, -20}";

        /*worksheet["C22"].Value = 10;
        worksheet["D22"].Value = -5;
        worksheet["E22"].Value = 2;
        worksheet["F22"].Value = 21;
        worksheet["G22"].Value = -20;*/

        worksheet["A24"].Value = "AVERAGE(IF(C22:G22>0,C22:G22,FALSE))";
        worksheet["A24"].Style.Font.Color = Color.DarkBlue;
        worksheet["A24"].AddComment("Calculate the average of the positive numbers in the range C22:G22");
        // add formula
        worksheet["C24"].FormulaArray = "=AVERAGE(IF(C22:G22>0,C22:G22,FALSE))";
        worksheet["C24"].Style = formulaResultStyle;

        // defined 2 named ranges to sum in a third range
        ExcelNamedRange firstRange = worksheet.NamedRanges.AddNamedRange(worksheet["C22:G22"], "FirstRange");
        ExcelNamedRange secondRange = worksheet.NamedRanges.AddNamedRange(worksheet["C7:G7"], "SecondRange");

        worksheet["A26"].Value = "FirstRange + SecondRange";
        worksheet["A26"].Style.Font.Color = Color.DarkBlue;
        worksheet["A26"].AddComment("Add the values from ranges C22:G22 and C7:G7 and assign the result to C26:G26");
        // add formula
        worksheet["C26:G26"].FormulaArray = "FirstRange + SecondRange";
        worksheet["C26:G26"].Style = formulaResultStyle;

        // evaluate workbook formulas

        // Save the Excel document in the current HTTP response stream

        string outFileName = workbookFormat == ExcelWorkbookFormat.Xls_2003 ? "FormulasDemo.xls" : "FormulasDemo.xlsx";

        System.Web.HttpResponse httpResponse = System.Web.HttpContext.Current.Response;

        // Prepare the HTTP response stream for saving the Excel document

        // Clear any data that might have been previously buffered in the output stream

        // Set output stream content type for Excel 97-2003 (.xls) or Excel 2007-2013 (.xlsx)
        if (workbookFormat == ExcelWorkbookFormat.Xls_2003)
            httpResponse.ContentType = "Application/x-msexcel";
            httpResponse.ContentType = "Application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";

        // Add the HTTP header to announce the Excel document either as an attachment or inline
        httpResponse.AddHeader("Content-Disposition", String.Format("attachment; filename={0}", outFileName));

        // Save the workbook to the current HTTP response output stream
        // and close the workbook after save to release all the allocated resources
        catch (Exception ex)
            // report any error that might occur during save
            Session["ErrorMessage"] = ex.Message;
            // close the workbook and release the allocated resources

            #region Dispose the Image object

            if (logoImg != null)


        // End the response and finish the execution of this page

ExpertXls Excel Spreadsheet Library for .NET