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

4 examples in Dashboards

Operations health dashboard

EnableSparklines EnableConditionalFormatting EnableShapes

Seven days of uptime per service, each row ending in a trend sparkline and an AVERAGE health figure graded by traffic-light icons — a status board that recalculates itself.

Write.cs

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

var opt = new ExcelStylingOptions { EnableSparklines = true, EnableConditionalFormatting = true, EnableShapes = true };
var title = ExcelStyle.Default.With(font: ExcelFontStyle.Default.With(bold: true, size: 16d, color: ExcelColor.FromRgb(255, 255, 255)), fill: ExcelFillStyle.Solid(ExcelColor.FromRgb(112, 48, 160)), alignment: ExcelAlignmentStyle.Default.With(horizontal: ExcelHorizontalAlignment.Center));
var head = ExcelStyle.Default.With(font: ExcelFontStyle.Default.With(bold: true, color: ExcelColor.FromRgb(255, 255, 255)), fill: ExcelFillStyle.Solid(ExcelColor.FromRgb(68, 68, 68)));
var pct = ExcelStyle.Default.With(numberFormat: ExcelNumberFormatStyle.Custom("0.0%"));

using (var writer = new ExcelStyledWriter("operations-health-dashboard.xlsx", null, opt))
{
    using (var sheet = writer.CreateWorksheet("Operations"))
    {
        sheet.MergeCells(1, 1, 1, 10);

        sheet.AddSparklineGroup(ExcelSparklineGroup.Create(new[]
        {
            ExcelSparkline.Create("'Operations'!$B$4:$H$4", 4, 9),
            ExcelSparkline.Create("'Operations'!$B$5:$H$5", 5, 9),
            ExcelSparkline.Create("'Operations'!$B$6:$H$6", 6, 9)
        }, type: ExcelSparklineType.Line, showMarkers: true, showHighPoint: true, showLowPoint: true));

        sheet.WriteRow(new object?[] { "Operations Health Dashboard" }, title);
        sheet.WriteRow();
        sheet.WriteRow(new object?[] { "Service", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun", "Trend", "Health" }, head);

        sheet.WriteRow(new object?[] { "Formula API", 0.98, 0.99, 0.97, 0.99, 1.00, 0.98, 0.99, null, ExcelFormula.From("AVERAGE(B4:H4)") }, new ExcelStyle?[] { null, pct, pct, pct, pct, pct, pct, pct, null, pct });
        sheet.WriteRow(new object?[] { "Import Worker", 0.91, 0.88, 0.94, 0.89, 0.93, 0.90, 0.92, null, ExcelFormula.From("AVERAGE(B5:H5)") }, new ExcelStyle?[] { null, pct, pct, pct, pct, pct, pct, pct, null, pct });
        sheet.WriteRow(new object?[] { "Export Worker", 0.82, 0.79, 0.85, 0.81, 0.78, 0.84, 0.80, null, ExcelFormula.From("AVERAGE(B6:H6)") }, new ExcelStyle?[] { null, pct, pct, pct, pct, pct, pct, pct, null, pct });

        sheet.AddConditionalFormat("J4:J6", ExcelConditionalFormat.IconSet(ExcelIconSet.ThreeTrafficLights1, new[]
        {
            ExcelConditionalFormatValue.Percent(0),
            ExcelConditionalFormatValue.Percent(50),
            ExcelConditionalFormatValue.Percent(80)
        }));

        sheet.AddShape(ExcelShape.Create(ExcelShapeKind.RoundedRectangle, ExcelDrawingAnchor.OneCell(2, 9, 260d, 70d), text: ExcelShapeText.Create("Weekly service health")));
    }

    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.

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