FormulaEngineer examples

Create, read, and style Excel workbooks in .NET.

Style workbooks as you write them — fonts, fills, borders, number formats, alignment, and layout — using ExcelStyledWriter. Every example below is a complete, runnable snippet.

Group

Cells and text 10 Layout 10 Conditional formatting 6 Named styles and themes 4 Tables and notes 10 Images and shapes 4 Charts and sparklines 6 Dashboards 4

Example

10 examples in Layout

Protected input sheet

Unlocks the cells a user is meant to edit, hides the formula text on calculated cells, and turns on sheet protection. Cosmetic guidance for the reader, not a security control.

Write.cs

using FormulaEngineer.Api;
using FormulaEngineer.Api.Styling;

var inputStyle =
    ExcelStyle.Default.With(
        fill: ExcelFillStyle.Solid(
            ExcelColor.FromRgb(255, 242, 204)),
        protection: ExcelProtectionStyle.Default.With(
            locked: false));

var formulaStyle =
    ExcelStyle.Default.With(
        numberFormat: ExcelNumberFormatStyle.Custom("$#,##0.00"),
        protection: ExcelProtectionStyle.Default.With(
            formulaHidden: true));

using (var writer = new ExcelStyledWriter("protected-input-sheet.xlsx"))
{
    using (var sheet = writer.CreateWorksheet("Protected"))
    {
        sheet.WriteRow("Item", "Qty", "Unit price", "Total");

        sheet.WriteRow(
            new object?[] { "License", 2, 499m, ExcelFormula.From("B2*C2") },
            new ExcelStyle?[] { null, inputStyle, inputStyle, formulaStyle });

        sheet.WriteRow(
            new object?[] { "Support", 1, 275m, ExcelFormula.From("B3*C3") },
            new ExcelStyle?[] { null, inputStyle, inputStyle, formulaStyle });

        sheet.ProtectSheet();
    }

    writer.Close();
}

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Style your own workbooks

Styling is part of the same package — no separate install, no Excel, no COM automation.

Get FormulaEngineer on NuGet Contact for styling questions