SmartExcelKit

SmartExcelKit is a lightweight, ultra-fast, low-allocation .NET Standard 2.0 library for reading, writing, streaming, and evaluating spreadsheet files across multiple formats (XLSX, XLS, CSV, TSV, HTML Table, XML Spreadsheet 2003, JSON).

Designed with performance as the top priority, SmartExcelKit uses pooled buffers (ArrayPool<T>), lazy enumerations, O(1) bounds caching, and forward-only streaming to deliver maximum throughput with minimal GC allocation.

Target Frameworks

.NET Standard 2.0: Compatible with .NET Core 2.0+, .NET 5+, .NET 6/7/8/9/10+, and .NET Framework 4.6.1+.

Installation

dotnet add package SmartExcelKit

Supported Formats

Format	Extension	Read	Write	Description
XLSX	`.xlsx`	✅	✅	Standard Microsoft Excel OpenXML Workbook
XLS	`.xls`	✅	❌	Legacy Microsoft Excel Binary Format (BIFF8 / OLE2)
CSV	`.csv`	✅	✅	Comma-Separated Values
TSV	`.tsv`	✅	✅	Tab-Separated Values
HTML	`.html`, `.htm`	✅	✅	HTML Table Spreadsheet Markup
XML 2003	`.xml`	✅	✅	Microsoft Excel 2003 XML SpreadsheetML
JSON	`.json`	✅	✅	Structured JSON Array / Document

Developer Guide & Complete Code Examples

1. Open Workbooks (Auto-Format Detection)

Load workbooks from file paths, streams, or byte arrays. Format is auto-detected from magic byte signatures or extensions.

using SmartExcelKit;
using SmartExcelKit.Core;

// 1. Open from file path (sync & async)
using var workbook1 = ExcelWorkbook.Open("data.xlsx");
using var workbook2 = await ExcelWorkbook.OpenAsync("data.csv");

// 2. Open from stream or byte array
using var stream = File.OpenRead("legacy.xls");
using var workbook3 = ExcelWorkbook.Open(stream);

byte[] bytes = File.ReadAllBytes("data.json");
using var workbook4 = ExcelWorkbook.Open(bytes);

// 3. Detect format explicitly
ExcelFileFormat format = ExcelWorkbook.DetectFormat(stream, "data.xlsx");

2. Create & Save Workbooks

Create workbooks, set active sheets, apply protection, and save to files or streams.

using SmartExcelKit;

using var workbook = new ExcelWorkbook();
var sheet = workbook.AddWorksheet("MainSheet");

// Set active worksheet
workbook.ActiveWorksheet = sheet;

// Workbook protection
workbook.Protect("WorkbookPassword123");
bool isProtected = workbook.IsProtected;
workbook.Unprotect();

// Save to file or stream (sync & async)
workbook.Save("output.xlsx");
await workbook.SaveAsync("output.xlsx");

using var outStream = File.Create("output.csv");
workbook.Save(outStream, ExcelFileFormat.Csv);

3. Worksheet Management & Navigation

Access sheets by name or 0-based index, remove sheets, or protect individual worksheets.

var sheet1 = workbook["MainSheet"];       // Access by name
var sheet2 = workbook[0];                 // Access by 0-based index

// Add / Remove worksheets
var newSheet = workbook.AddWorksheet("Draft");
workbook.RemoveWorksheet("Draft");

// Worksheet protection
sheet1.Protect("SheetPassword123");
sheet1.Unprotect();

4. Row & Column Operations

Manage heights, widths, visibility, grouping, auto-fit, and insert/delete operations.

var sheet = workbook.ActiveWorksheet;

// Row properties
ExcelRow row = sheet.Row(1);
row.Height = 30.0;
row.Hidden = false;

// Column properties
ExcelColumn col = sheet.Column(1); // Column 'A'
col.Width = 25.0;
col.AutoFit();                     // Auto-fit column width based on content

// Insert & Delete Rows / Columns
sheet.InsertRows(startRow: 2, count: 5);
sheet.DeleteRows(startRow: 10, count: 2);

sheet.InsertColumns(startColumn: 2, count: 1);
sheet.DeleteColumns(startColumn: 5, count: 1);

// Group & Ungroup Rows / Columns
sheet.GroupRows(fromRow: 2, toRow: 10);
sheet.UngroupRows(fromRow: 2, toRow: 10);

sheet.GroupColumns(fromColumn: 1, toColumn: 3);
sheet.UngroupColumns(fromColumn: 1, toColumn: 3);

// First & Last Used Row / Column
ExcelRow? firstRow = sheet.FirstRowUsed();
ExcelRow? lastRow  = sheet.LastRowUsed();
ExcelColumn? firstCol = sheet.FirstColumnUsed();
ExcelColumn? lastCol  = sheet.LastColumnUsed();

5. Cell Reading & Writing (Type-Safe Getters)

Set and read cell values with type safety and fallback default values.

// Cell assignment via address string or row/column numbers
sheet.Cell("A1").Value = "Product Name";
sheet.Cell(1, 2).Value = 199.99;
sheet["A3"].Value = DateTime.UtcNow;
sheet[1, 4].Value = true;

// Type-safe getters
ExcelCell cell = sheet.Cell("B1");

string strVal  = cell.GetString();
int intVal     = cell.GetInt32();
long longVal   = cell.GetInt64();
double dblVal  = cell.GetDouble();
decimal decVal = cell.GetDecimal();
bool boolVal   = cell.GetBoolean();
DateTime dtVal = cell.GetDateTime();

// Generic getter & TryGetValue with fallback
if (cell.HasValue)
{
    double val = cell.GetValue<double>();
    
    if (cell.TryGetValue<int>(out int parsedCount))
    {
        Console.WriteLine($"Count: {parsedCount}");
    }
}

int fallback = cell.GetValueOrDefault<int>(defaultValue: 0);

6. Range Operations & Bulk Matrix Access

Perform bulk formatting, matrix assignments, clearing, merging, and copying.

var range = sheet.Range("A1:D10");
// Or range by coordinates: sheet.Range(startRow: 1, startColumn: 1, endRow: 10, endColumn: 4);

// Merge & Unmerge
range.Merge();
range.Unmerge();

// Clear Operations
range.ClearContents(); // Clears values and formulas
range.ClearStyles();   // Resets styles to default
range.Clear();         // Clears values, formulas, styles, comments, hyperlinks

// Bulk Copy
var targetRange = sheet.Range("F1:I10");
range.CopyTo(targetRange);

// Bulk Matrix Value Assignment & Extraction
object?[,] matrix = new object?[,]
{
    { "ID", "Name", "Price" },
    { 101, "Keyboard", 89.99 },
    { 102, "Mouse", 29.99 }
};
sheet.SetValues(matrix, startRow: 1, startColumn: 1);

object?[,] extracted = sheet.GetValues(startRow: 1, startColumn: 1, endRow: 3, endColumn: 3);

7. Cell Styling & Number Formatting

Customize fonts, fills, borders, alignments, and number format strings.

using SmartExcelKit.Styles;

var customStyle = new ExcelStyle(
    font: new ExcelFont(name: "Arial", size: 12, bold: true, italic: false, underline: true, color: "1F4E79"),
    fill: new ExcelFill(ExcelFillPatternType.Solid, backgroundColor: "EBF1F5"),
    border: new ExcelBorder(
        left: new ExcelBorderItem(ExcelBorderStyle.Thin, color: "000000"),
        right: new ExcelBorderItem(ExcelBorderStyle.Thin, color: "000000"),
        top: new ExcelBorderItem(ExcelBorderStyle.Medium, color: "1F4E79"),
        bottom: new ExcelBorderItem(ExcelBorderStyle.Medium, color: "1F4E79")
    ),
    alignment: new ExcelAlignment(
        horizontal: ExcelHorizontalAlignment.Center,
        vertical: ExcelVerticalAlignment.Center,
        wrapText: true,
        indent: 1
    ),
    numberFormat: new ExcelNumberFormat("$#,##0.00")
);

// Apply style to cell or range
sheet.Cell("B2").Style = customStyle;
sheet.Range("A1:D1").Style = customStyle;

8. Excel Tables (ListObject) & Totals Row

Create native Excel Tables with custom styles and totals row aggregations.

using SmartExcelKit.Tables;

var table = sheet.Tables.Add("A1:C10", "SalesTable");

// Table Properties
table.StyleName = "TableStyleMedium9";
table.ShowHeaderRow = true;
table.ShowTotalsRow = true;
table.ShowStripedRows = true;
table.ShowStripedColumns = false;

// Configure Totals Row Functions for Columns
table["Price"].TotalsRowFunction = TotalsRowFunction.Average;
table["Quantity"].TotalsRowFunction = TotalsRowFunction.Sum;
table["ID"].TotalsRowFunction = TotalsRowFunction.Count;

9. AutoFilter & Multi-Column Sorting

Enable AutoFilters and perform multi-column, culture-aware sorting.

// Enable AutoFilter over specific range or used range
sheet.AutoFilter("A1:D100");
sheet.ClearAutoFilter();

// Multi-column sorting: sort rows 2-100 by Column 2 (ascending)
sheet.Sort(
    startRow: 2, startColumn: 1,
    endRow: 100, endColumn: 4,
    sortColumn: 2,
    ascending: true,
    culture: System.Globalization.CultureInfo.CurrentCulture
);

10. Conditional Formatting

Apply color scales, data bars, value comparisons, or formula rules.

using SmartExcelKit.Formatting;
using SmartExcelKit.Styles;

// 1. Cell Value Rule (Highlight values > 500 in red)
var alertStyle = new ExcelStyle(font: new ExcelFont(bold: true, color: "FF0000"));
sheet.ConditionalFormatting.AddCellValueRule("C2:C100", ConditionalFormattingOperator.GreaterThan, "500", alertStyle);

// 2. Data Bar Gradient Visualization
sheet.ConditionalFormatting.AddDataBar("D2:D100", colorHex: "00FF00");

// 3. 2-Color & 3-Color Scales
sheet.ConditionalFormatting.AddTwoColorScale("E2:E100", minColorHex: "FFFFFF", maxColorHex: "0000FF");
sheet.ConditionalFormatting.AddThreeColorScale("F2:F100", minColorHex: "FF0000", midColorHex: "FFFF00", maxColorHex: "00FF00");

// 4. Formula Rule
sheet.ConditionalFormatting.AddFormulaRule("A2:A100", "ISODD(ROW())", alertStyle);

11. Data Validation Rules

Add drop-down lists, numeric ranges, text length limits, date constraints, or custom formulas.

using SmartExcelKit.Validation;

// 1. List Validation (Drop-down menu)
sheet.DataValidations.AddListValidation("A2:A100", new[] { "Approved", "Pending", "Rejected" });

// 2. Whole Number & Decimal Validation
sheet.DataValidations.AddWholeNumberValidation("B2:B100", ValidationOperator.Between, min: 1, max: 100);
sheet.DataValidations.AddDecimalValidation("C2:C100", ValidationOperator.GreaterThan, min: 0.0);

// 3. Date & Text Length Validation
sheet.DataValidations.AddDateValidation("D2:D100", ValidationOperator.GreaterThanOrEqual, minDate: DateTime.Today);
sheet.DataValidations.AddTextLengthValidation("E2:E100", ValidationOperator.LessThanOrEqual, maxLen: 50);

// 4. Custom Formula Validation & Alert Configuration
var customVal = sheet.DataValidations.AddCustomValidation("F2:F100", "=AND(F2>0, F2<1000)");
customVal.ShowErrorMessage = true;
customVal.ErrorTitle = "Invalid Entry";
customVal.ErrorMessage = "Value must be between 0 and 1000.";

12. Formula Engine & Recalculation

Evaluate 60+ built-in functions with dependency tracking and calculation caching.

using SmartExcelKit.Formula;

sheet["A1"].Value = 100;
sheet["A2"].Value = 200;
sheet["A3"].Formula = "SUM(A1:A2)";
sheet["A4"].Formula = "AVERAGE(A1:A3)";
sheet["A5"].Formula = "VLOOKUP(100, A1:A2, 1, FALSE)";

// Recalculate dependent cell formulas across the entire workbook
workbook.Recalculate();

// Evaluate formula directly without placing it in a cell
object? evalResult = FormulaEvaluator.Evaluate("MAX(A1:A2) * 1.1", sheet);
Console.WriteLine($"Result: {evalResult}");

13. Rich Text, Hyperlinks & Cell Comments

Attach formatted text runs, hyperlinks, and styled notes to cells.

using SmartExcelKit.Core;

var cell = sheet["A1"];

// 1. Rich Text
var rich = new RichText();
rich.AddBold("Status: ", fontSize: 11, fontColorHex: "0000FF");
rich.AddItalic("Action Required", fontSize: 10, fontColorHex: "FF0000");
cell.RichText = rich;

// 2. Hyperlinks (Internal, External, Email, File)
cell.HyperlinkObject = ExcelHyperlink.External("https://github.com", tooltip: "Open Web Site");
cell.HyperlinkObject = ExcelHyperlink.Internal("Sheet2", "B5", tooltip: "Jump to Sheet2");
cell.HyperlinkObject = ExcelHyperlink.Email("support@example.com", subject: "Inquiry");

// 3. Cell Comments
cell.CommentObject = new ExcelComment("Please verify this figure before publishing.", author: "Financial Controller");

14. Images, Native Charts & Pivot Tables

Embed visual elements directly into worksheets.

using SmartExcelKit.Drawings;
using SmartExcelKit.Core;

// 1. Embedded Image (PNG, JPEG, SVG, GIF, BMP)
var img = ExcelImage.FromFile("logo.png", topRow: 1, leftColumn: 5, width: 200, height: 100);
sheet.Images.Add(img);

// 2. Native Chart (Column, Bar, Line, Pie, Area, Scatter, Doughnut)
var chart = new ExcelChart(ChartType.Column, topRow: 5, leftColumn: 5, width: 450, height: 300);
chart.Title = "Quarterly Revenue";
chart.AddSeries("Sales", "Sheet1!B2:B10");
sheet.Charts.Add(chart);

// 3. Embedded Pivot Table
var pivot = new ExcelPivotTable("SalesPivot", "Sheet1!A1:D100", targetCell: new CellAddress(15, 5));
pivot.AddRowField("Category");
pivot.AddColumnField("Year");
pivot.AddDataField("Revenue", PivotSummaryFunction.Sum);
pivot.AddFilterField("Region");
sheet.PivotTables.Add(pivot);

15. Page Setup & Print Settings

Configure orientation, paper size, print areas, margins, and headers/footers.

using SmartExcelKit.PageSetup;

var setup = sheet.PageSetup;
setup.Orientation = PageOrientation.Landscape;
setup.PaperSize = PaperSize.A4;
setup.PrintArea = "A1:G50";
setup.PrintGridlines = true;
setup.PrintHeadings = true;

// Fit to Pages
setup.FitToPages = true;
setup.FitToWidth = 1;
setup.FitToHeight = 2;

// Headers & Footers
setup.HeaderCenter = "Quarterly Financial Report";
setup.FooterRight = "Page 1 of 10";

// Margins (in inches)
setup.MarginLeft = 0.75;
setup.MarginRight = 0.75;
setup.MarginTop = 1.0;
setup.MarginBottom = 1.0;

16. Named Ranges (Workbook & Worksheet Scoped)

Create and manage named ranges globally or scoped to a specific worksheet.

using SmartExcelKit.Core;

// Workbook-scoped named range
workbook.NamedRanges.Add("GlobalTaxRate", "Sheet1!$Z$1");

// Worksheet-scoped named range
sheet.NamedRanges.Add("LocalData", "Sheet1!$A$1:$D$50");

// Access named range
ExcelNamedRange taxRange = workbook.NamedRanges["GlobalTaxRate"];

17. High-Performance Streaming Reader & Writer

Process giant XLSX files with 1,000,000+ rows under 15 MB RAM.

using SmartExcelKit.Streaming;

// 1. Streaming Writer (Flat memory write)
using var outStream = File.Create("large_export.xlsx");
using var writer = new ExcelStreamingWriter(outStream);

writer.BeginSheet("Data");
writer.WriteRow(new object?[] { "ID", "User", "Timestamp" });

// Sync & Async row streaming
for (int i = 1; i <= 1000000; i++)
{
    writer.WriteRow(new object?[] { i, $"User_{i}", DateTime.UtcNow });
}
await writer.WriteRowAsync(new object?[] { 1000001, "FinalUser", DateTime.UtcNow });

writer.EndSheet();

// 2. Streaming Reader (Sync & Async forward-only read)
using var inStream = File.OpenRead("large_export.xlsx");
using var reader = new ExcelStreamingReader(inStream);

foreach (string sheetName in reader.GetSheets())
{
    foreach (object?[] rowValues in reader.ReadRows(sheetName))
    {
        // Process row without memory overhead
    }

    List<object?[]> allRowsAsync = await reader.ReadRowsAsync(sheetName);
}

18. Delimited CSV & TSV Engine

High-speed character buffer streaming parser for CSV/TSV files.

using SmartExcelKit.Csv;

// 1. Detect Encoding & Delimiter automatically
using var readStream = File.OpenRead("data.csv");
var encoding = CsvEngine.DetectEncoding(readStream);
char delimiter = CsvEngine.DetectDelimiter(readStream, encoding);

// 2. Read Streaming
foreach (List<string> rowFields in CsvEngine.ReadStreaming(readStream, delimiter, encoding))
{
    Console.WriteLine($"Col 0: {rowFields[0]}, Col 1: {rowFields[1]}");
}

// 3. Write CSV
var rows = new List<List<string>>
{
    new() { "ID", "Name" },
    new() { "1", "Alice" }
};
using var writeStream = File.Create("export.csv");
CsvEngine.Write(writeStream, rows, delimiter: ',');

19. POCO & DataTable Integration

Import C# object collections or DataTables into worksheets, or export them back.

using System.Data;

public class Product
{
    public string Name { get; set; } = string.Empty;
    public double Price { get; set; }
    public int Quantity { get; set; }
}

var products = new List<Product>
{
    new() { Name = "Laptop", Price = 999.99, Quantity = 5 },
    new() { Name = "Mouse", Price = 25.50, Quantity = 40 }
};

// 1. POCO Import & Export
sheet.Import(products, startRow: 1, startColumn: 1, includeHeader: true);
List<Product> exportedProducts = sheet.Export<Product>(startRow: 1, startColumn: 1).ToList();

// 2. DataTable Import & Export
var dt = new DataTable("Orders");
dt.Columns.Add("ID", typeof(int));
dt.Columns.Add("Customer", typeof(string));
dt.Rows.Add(1, "Acme Corp");

sheet.Import(dt, startRow: 1, startColumn: 1, includeHeader: true);
DataTable exportedDt = sheet.ExportToDataTable(startRow: 1, startColumn: 1, hasHeader: true);

20. Developer One-Liner Export & Conversion Helpers

Quickly convert entire workbooks, worksheets, or rows directly to CSV, JSON, DataSet, DataTable, Dictionaries, or POCO collections without writing manual loops.

using System.Data;

// 1. Workbook-Level One-Liners (Aggregates across ALL worksheets in the workbook)
string fullWorkbookCsv  = workbook.ToCsv(delimiter: ',');
string fullWorkbookJson = workbook.ToJson(hasHeader: true);
DataSet workbookDataSet = workbook.ToDataSet(hasHeader: true);    // DataSet containing DataTables per sheet
DataTable activeSheetDt = workbook.ToDataTable(hasHeader: true);
List<Product> allPocos  = workbook.ToObjects<Product>().ToList();   // Maps POCOs across all sheets
var allSheetDicts       = workbook.ToDictionaryList();             // List of dictionaries with '__Worksheet' key

// 2. Worksheet-Level One-Liners
string csvString   = sheet.ToCsv(delimiter: ',');
string jsonString  = sheet.ToJson(hasHeader: true);
DataTable dataTbl  = sheet.ToDataTable(hasHeader: true);
var dictList       = sheet.ToDictionaryList(startRow: 1);
List<Product> list = sheet.ToObjects<Product>().ToList();

// 3. Row-Level & Cell Helpers
foreach (var row in sheet.RowsUsed())
{
    string rowCsv                 = row.ToCsv();
    object?[] rowValues           = row.Values();
    Dictionary<string, object?> d = row.ToDictionary(headerRow: 1);
    Product p                     = row.ToObject<Product>(headerRow: 1);
    bool blank                    = row.IsBlank();
    ExcelCell? firstCell          = row.FirstCellUsed();
    ExcelCell? lastCell           = row.LastCellUsed();
}

License

This project is licensed under the MIT License.

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

SmartExcelKit

Target Frameworks

Installation

Supported Formats

Developer Guide & Complete Code Examples

1. Open Workbooks (Auto-Format Detection)

2. Create & Save Workbooks

3. Worksheet Management & Navigation

4. Row & Column Operations

5. Cell Reading & Writing (Type-Safe Getters)

6. Range Operations & Bulk Matrix Access

7. Cell Styling & Number Formatting

8. Excel Tables (ListObject) & Totals Row

9. AutoFilter & Multi-Column Sorting

10. Conditional Formatting

11. Data Validation Rules

12. Formula Engine & Recalculation

13. Rich Text, Hyperlinks & Cell Comments

14. Images, Native Charts & Pivot Tables

15. Page Setup & Print Settings

16. Named Ranges (Workbook & Worksheet Scoped)

17. High-Performance Streaming Reader & Writer

18. Delimited CSV & TSV Engine

19. POCO & DataTable Integration

20. Developer One-Liner Export & Conversion Helpers

License

FilesExpand file tree

README.md

Latest commit

History

README.md

File metadata and controls

SmartExcelKit

Target Frameworks

Installation

Supported Formats

Developer Guide & Complete Code Examples

1. Open Workbooks (Auto-Format Detection)

2. Create & Save Workbooks

3. Worksheet Management & Navigation

4. Row & Column Operations

5. Cell Reading & Writing (Type-Safe Getters)

6. Range Operations & Bulk Matrix Access

7. Cell Styling & Number Formatting

8. Excel Tables (ListObject) & Totals Row

9. AutoFilter & Multi-Column Sorting

10. Conditional Formatting

11. Data Validation Rules

12. Formula Engine & Recalculation

13. Rich Text, Hyperlinks & Cell Comments

14. Images, Native Charts & Pivot Tables

15. Page Setup & Print Settings

16. Named Ranges (Workbook & Worksheet Scoped)

17. High-Performance Streaming Reader & Writer

18. Delimited CSV & TSV Engine

19. POCO & DataTable Integration

20. Developer One-Liner Export & Conversion Helpers

License