👁 Image
OfficeIMO.Excel 0.6.46

OfficeIMO.Excel - Excel workbooks for .NET

👁 nuget version
👁 nuget downloads

OfficeIMO.Excel is the main Excel package in the OfficeIMO family. It creates, edits, reads, and saves .xlsx workbooks without COM automation and without Microsoft Excel installed.

If OfficeIMO saves you time, please consider supporting the work through GitHub Sponsors or PayPal. PowerShell users should use PSWriteOffice for the PowerShell-facing experience.

Install

dotnet add package OfficeIMO.Excel

Quick start

using OfficeIMO.Excel;

using var document = ExcelDocument.Create("report.xlsx");
var sheet = document.AddWorkSheet("Data");

sheet.CellValue(1, 1, "Name");
sheet.CellValue(1, 2, "Value");
sheet.CellValue(2, 1, "Alpha");
sheet.CellValue(2, 2, 42);
sheet.AddTable("A1:B2", hasHeader: true, name: "DataTable", style: TableStyle.TableStyleMedium9);
sheet.AutoFitColumns();

document.Save();

What it does

• Creates and edits workbooks, worksheets, cells, ranges, tables, styles, hyperlinks, formulas, names, comments, images, charts, filters, and page setup.
• Reads values through worksheet, range, row, dictionary, stream, and typed object helpers.
• Supports editable row workflows where rows can be read, changed, and saved back.
• Handles practical workbook hygiene such as table/filter conflicts, safe table names, deterministic save order, and feature inspection.
• Includes parallel execution controls for heavy export and autofit workloads while serializing the Open XML mutation phase safely.

Examples

The quick start covers the smallest workbook. These examples show common read, write, reporting, and automation workflows that belong in OfficeIMO.Excel.

Read rows by header

using var document = ExcelDocument.Load("input.xlsx");
var sheet = document["Data"];

foreach (var row in sheet.Rows()) {
 Console.WriteLine(row["Name"]);
}

Map rows to objects

using var document = ExcelDocument.Load("input.xlsx");
List<Person> people = document["Data"].RowsAs<Person>("A1:C100").ToList();

public sealed class Person {
 public string Name { get; set; } = "";
 public int Value { get; set; }
 public string Status { get; set; } = "";
}

Append to an existing table

using var document = ExcelDocument.Load("sales.xlsx");
var rows = new DataTable();
rows.Columns.Add("Revenue", typeof(decimal));
rows.Columns.Add("Region", typeof(string));
rows.Rows.Add(150m, "APAC");

document["Sales"].AppendDataTableToTable(rows, "SalesTable");
document.Save();

Validation lists and typed reads

using var document = ExcelDocument.Load("input.xlsx");
var sheet = document["Data"];

sheet.ValidationList("C2:C100", new[] { "New", "Processed", "Hold" });
sheet.Range("D2:D100").Validate.WholeNumberBetween(1, 10, errorMessage: "Use 1 through 10");

List<RowModel> rows = document.Read()
 .Sheet("Data")
 .Range("A1:C100")
 .AsObjects<RowModel>()
 .ToList();

public sealed class RowModel {
 public string Name { get; set; } = "";
 public string Status { get; set; } = "";
}

Charts and dashboard recipes

using OfficeIMO.Excel;

using var document = ExcelDocument.Create("dashboard.xlsx");
var sheet = document.AddWorkSheet("Summary");

sheet.CellValue(1, 1, "Quarter");
sheet.CellValue(1, 2, "Revenue");
sheet.CellValue(2, 1, "Q1");
sheet.CellValue(2, 2, 10);
sheet.CellValue(3, 1, "Q2");
sheet.CellValue(3, 2, 18);
sheet.CellValue(4, 1, "Q3");
sheet.CellValue(4, 2, 24);
sheet.CellValue(5, 1, "Q4");
sheet.CellValue(5, 2, 30);

sheet.AddTable("A1:B5", hasHeader: true, name: "RevenueTable", style: TableStyle.TableStyleMedium2);
sheet.ChartFromTable("RevenueTable")
 .RevenueTrend("Revenue trend")
 .Size(640, 320)
 .At(row: 1, column: 5);

document.Save();

Pivot tables and pivot-backed charts

using OfficeIMO.Excel;
using System.Linq;

using var document = ExcelDocument.Create("pivot-report.xlsx");
var sheet = document.AddWorkSheet("Sales");

sheet.CellValue(1, 1, "Region");
sheet.CellValue(1, 2, "Product");
sheet.CellValue(1, 3, "Quarter");
sheet.CellValue(1, 4, "Revenue");
sheet.CellValue(2, 1, "EMEA");
sheet.CellValue(2, 2, "Alpha");
sheet.CellValue(2, 3, "Q1");
sheet.CellValue(2, 4, 125000);
sheet.CellValue(3, 1, "EMEA");
sheet.CellValue(3, 2, "Beta");
sheet.CellValue(3, 3, "Q1");
sheet.CellValue(3, 4, 94000);
sheet.CellValue(4, 1, "APAC");
sheet.CellValue(4, 2, "Alpha");
sheet.CellValue(4, 3, "Q2");
sheet.CellValue(4, 4, 141000);
sheet.AddTable("A1:D4", hasHeader: true, name: "SalesTable", style: TableStyle.TableStyleMedium4);

sheet.Pivot("A1:D4")
 .Rows("Region")
 .Columns("Quarter")
 .Filters("Product")
 .Sum("Revenue", "Total revenue", "#,##0")
 .Layout(ExcelPivotLayout.Tabular)
 .Style("PivotStyleMedium9")
 .Captions(rowHeader: "Region", columnHeader: "Quarter", grandTotal: "Total")
 .At("F2", "SalesPivot");

var pivot = sheet.GetPivotTables().Single(p => p.Name == "SalesPivot");
Console.WriteLine($"{pivot.Name}: {string.Join(", ", pivot.RowFields)}");

var chart = sheet.ChartFromTable("SalesTable")
 .VarianceColumns("Revenue by region")
 .At(row: 12, column: 1);
chart.SetPivotSource("SalesPivot");

document.Save();

Pivot support is useful but still marked partial in the compatibility matrix. It covers source-range pivots, row/column/page/data fields, styles, layouts, filters, calculated fields, grouping metadata, and readback. Slicers, timelines, external connections, and query-table authoring are still preserve-oriented or roadmap areas.

Formula inspection and calculation policy

using var document = ExcelDocument.Load("report.xlsx");

var formulas = document.InspectFormulas();
Console.WriteLine(formulas.ToMarkdown());

foreach (var formula in formulas.Formulas.Where(f => !f.IsSupportedByOfficeIMO)) {
 Console.WriteLine($"{formula.SheetName}!{formula.CellReference}: {formula.UnsupportedReason}");
}

int calculated = document.Calculate();
document.Save("report.xlsx", openExcel: false, options: new ExcelSaveOptions {
 EvaluateFormulasBeforeSave = true,
 ForceFullCalculationOnOpen = true
});

CSV and JSON exchange

using System.Data;

using var document = ExcelDocument.Load("data.xlsx");
var sheet = document["Data"];

DataTable table = sheet.ToDataTable("A1:C100");
string csv = sheet.ToCsv("A1:C100");
string json = sheet.ToJson("A1:C100");

sheet.FromCsv("Name,Amount\nAlpha,10\nBeta,20", startRow: 5, startColumn: 1);
sheet.FromJson("[{\"Name\":\"Gamma\",\"Amount\":30}]", startRow: 8, startColumn: 1);

Template markers

using var document = ExcelDocument.Load("invoice-template.xlsx");

int replacements = document.ApplyTemplate(new Dictionary<string, object?> {
 ["Invoice.Number"] = "INV-001",
 ["Customer.Name"] = "Adatum",
 ["Total"] = 123.45m
});

var template = document.InspectTemplate(new {
 Invoice = new { Number = "INV-001" },
 Customer = new { Name = "Adatum" },
 Total = 123.45m
});

template.EnsureAllMarkersBound();
document.Save("invoice.xlsx");

Comments and conditional formatting

using var document = ExcelDocument.Load("review.xlsx");
var sheet = document["Data"];

sheet.SetComment("A1", "Review total", author: "Alice", initials: "AA");
sheet.UpdateComments(new ExcelCommentFilter { TextContains = "total" }, "Total reviewed", author: "Carol", initials: "CC");

sheet.AddConditionalColorScale("C2:C100", "#FFF0F0", "#70AD47");
sheet.Range("D2:D100").ConditionalFormat.DataBar("#5B9BD5");

document.Save();

Tune larger exports

using var document = ExcelDocument.Create("large-report.xlsx");
document.Execution.Mode = ExecutionMode.Automatic;
document.Execution.MaxDegreeOfParallelism = Environment.ProcessorCount;
document.Execution.SaveWorksheetAfterAutoFit = false;

Fluent compose

using var document = ExcelDocument.Create("composed-report.xlsx");

document.Compose("Report", composer => {
 composer.Title("Demo Report", "Generated with OfficeIMO.Excel");
 composer.Callout("info", "Heads up", "Generated via the fluent API");
 composer.Section("Summary");
 composer.PropertiesGrid(new (string, object?)[] {
 ("Author", "OfficeIMO"),
 ("Date", DateTime.Today.ToString("yyyy-MM-dd"))
 });

 var items = new[] {
 new { Name = "Alice", Score = 90, Status = "OK" },
 new { Name = "Bob", Score = 80, Status = "Warning" }
 };

 composer.TableFrom(items, title: "Scores", visuals: visuals => {
 visuals.NumericColumnDecimals["Score"] = 0;
 visuals.TextBackgrounds["Status"] = new Dictionary<string, string> {
 ["Warning"] = "#FFF3CD"
 };
 });

 composer.HeaderFooter(header => header.Center("Demo Report").FooterRight("Page &P of &N"));
 composer.Finish(autoFitColumns: true);
});

document.Save();

Adjacent packages

Boundaries

• OfficeIMO.Excel owns workbook modeling and Open XML read/write behavior.
• PDF layout belongs in OfficeIMO.Excel.Pdf and OfficeIMO.Pdf.
• Google Sheets export orchestration belongs in OfficeIMO.Excel.GoogleSheets.
• Long benchmark results and compatibility matrices belong in Docs/, not this README.

Deeper docs

Targets and license

• Targets: netstandard2.0, net8.0, net10.0; net472 is included when building on Windows.
• License: MIT.
• Repository: EvotecIT/OfficeIMO