Create an excel document from C#

create-excel.cs

#r "DocumentFormat.OpenXml"

using System.IO;
using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;

var filepath = "/Users/mkuckert/test.xlsx";
var stream = File.Open(filepath, FileMode.OpenOrCreate, FileAccess.ReadWrite);

var document = SpreadsheetDocument.Create(stream, SpreadsheetDocumentType.Workbook);

var workbook = new Workbook();
var workbookPart = document.AddWorkbookPart();
workbookPart.Workbook = workbook;

// Add Sheets to the Workbook.
var sheets = workbook.AppendChild(new Sheets());

var row = new Row(new Cell{DataType=CellValues.String, CellValue=new CellValue("foo")});
var data = new SheetData(row);

var worksheet = new Worksheet(data);
var worksheetPart = workbookPart.AddNewPart<WorksheetPart>();
worksheetPart.Worksheet = worksheet;

var sheet = new Sheet
{
    Id = workbookPart.GetIdOfPart(worksheetPart),
    SheetId = 1,
    Name = "name"
};
sheets.AppendChild(sheet);

document.Dispose();