How to Create an Excel File in C# (.NET Tutorial)

workSheet["A1"].Value = "January";
workSheet["B1"].Value = "February";
workSheet["C1"].Value = "March";
workSheet["D1"].Value = "April";
workSheet["E1"].Value = "May";
workSheet["F1"].Value = "June";
workSheet["G1"].Value = "July";
workSheet["H1"].Value = "August";
workSheet["I1"].Value = "September";
workSheet["J1"].Value = "October";
workSheet["K1"].Value = "November";
workSheet["L1"].Value = "December";

workSheet("A1").Value = "January"
workSheet("B1").Value = "February"
workSheet("C1").Value = "March"
workSheet("D1").Value = "April"
workSheet("E1").Value = "May"
workSheet("F1").Value = "June"
workSheet("G1").Value = "July"
workSheet("H1").Value = "August"
workSheet("I1").Value = "September"
workSheet("J1").Value = "October"
workSheet("K1").Value = "November"
workSheet("L1").Value = "December"

Random r = new Random();
for (int i = 2 ; i <= 11 ; i++)
{
    workSheet["A" + i].Value = r.Next(1, 1000);
    workSheet["B" + i].Value = r.Next(1000, 2000);
    workSheet["C" + i].Value = r.Next(2000, 3000);
    workSheet["D" + i].Value = r.Next(3000, 4000);
    workSheet["E" + i].Value = r.Next(4000, 5000);
    workSheet["F" + i].Value = r.Next(5000, 6000);
    workSheet["G" + i].Value = r.Next(6000, 7000);
    workSheet["H" + i].Value = r.Next(7000, 8000);
    workSheet["I" + i].Value = r.Next(8000, 9000);
    workSheet["J" + i].Value = r.Next(9000, 10000);
    workSheet["K" + i].Value = r.Next(10000, 11000);
    workSheet["L" + i].Value = r.Next(11000, 12000);
}

Dim r As New Random()
For i As Integer = 2 To 11
	workSheet("A" & i).Value = r.Next(1, 1000)
	workSheet("B" & i).Value = r.Next(1000, 2000)
	workSheet("C" & i).Value = r.Next(2000, 3000)
	workSheet("D" & i).Value = r.Next(3000, 4000)
	workSheet("E" & i).Value = r.Next(4000, 5000)
	workSheet("F" & i).Value = r.Next(5000, 6000)
	workSheet("G" & i).Value = r.Next(6000, 7000)
	workSheet("H" & i).Value = r.Next(7000, 8000)
	workSheet("I" & i).Value = r.Next(8000, 9000)
	workSheet("J" & i).Value = r.Next(9000, 10000)
	workSheet("K" & i).Value = r.Next(10000, 11000)
	workSheet("L" & i).Value = r.Next(11000, 12000)
Next i

// Initialize random number generator for sample data
Random r = new Random();

// Populate cells with random budget data for each month
for (int i = 2; i <= 11; i++)
{
    // Set different budget categories with increasing ranges
    workSheet[$"A{i}"].Value = r.Next(1, 1000);     // Office Supplies
    workSheet[$"B{i}"].Value = r.Next(1000, 2000);  // Utilities
    workSheet[$"C{i}"].Value = r.Next(2000, 3000);  // Rent
    workSheet[$"D{i}"].Value = r.Next(3000, 4000);  // Salaries
    workSheet[$"E{i}"].Value = r.Next(4000, 5000);  // Marketing
    workSheet[$"F{i}"].Value = r.Next(5000, 6000);  // IT Services
    workSheet[$"G{i}"].Value = r.Next(6000, 7000);  // Travel
    workSheet[$"H{i}"].Value = r.Next(7000, 8000);  // Training
    workSheet[$"I{i}"].Value = r.Next(8000, 9000);  // Insurance
    workSheet[$"J{i}"].Value = r.Next(9000, 10000); // Equipment
    workSheet[$"K{i}"].Value = r.Next(10000, 11000); // Research
    workSheet[$"L{i}"].Value = r.Next(11000, 12000); // Misc
}

// Alternative: Set range of cells with same value
workSheet["A13:L13"].Value = 0; // Initialize totals row

' Initialize random number generator for sample data
Dim r As New Random()

' Populate cells with random budget data for each month
For i As Integer = 2 To 11
	' Set different budget categories with increasing ranges
	workSheet($"A{i}").Value = r.Next(1, 1000) ' Office Supplies
	workSheet($"B{i}").Value = r.Next(1000, 2000) ' Utilities
	workSheet($"C{i}").Value = r.Next(2000, 3000) ' Rent
	workSheet($"D{i}").Value = r.Next(3000, 4000) ' Salaries
	workSheet($"E{i}").Value = r.Next(4000, 5000) ' Marketing
	workSheet($"F{i}").Value = r.Next(5000, 6000) ' IT Services
	workSheet($"G{i}").Value = r.Next(6000, 7000) ' Travel
	workSheet($"H{i}").Value = r.Next(7000, 8000) ' Training
	workSheet($"I{i}").Value = r.Next(8000, 9000) ' Insurance
	workSheet($"J{i}").Value = r.Next(9000, 10000) ' Equipment
	workSheet($"K{i}").Value = r.Next(10000, 11000) ' Research
	workSheet($"L{i}").Value = r.Next(11000, 12000) ' Misc
Next i

' Alternative: Set range of cells with same value
workSheet("A13:L13").Value = 0 ' Initialize totals row

workSheet["A1:L1"].Style.SetBackgroundColor("#d3d3d3");

workSheet("A1:L1").Style.SetBackgroundColor("#d3d3d3")

// Set header row background to light gray using hex color
workSheet["A1:L1"].Style.SetBackgroundColor("#d3d3d3");

// Apply different colors for data categorization
workSheet["A2:A11"].Style.SetBackgroundColor("#E7F3FF"); // Light blue for January
workSheet["B2:B11"].Style.SetBackgroundColor("#FFF2CC"); // Light yellow for February

// Highlight important cells with bold colors
workSheet["L12"].Style.SetBackgroundColor("#FF0000"); // Red for totals
workSheet["L12"].Style.Font.FontColor = "#FFFFFF"; // White text

// Create alternating row colors for better readability
for (int row = 2; row <= 11; row++)
{
    if (row % 2 == 0)
    {
        workSheet[$"A{row}:L{row}"].Style.SetBackgroundColor("#F2F2F2");
    }
}

' Set header row background to light gray using hex color
workSheet("A1:L1").Style.SetBackgroundColor("#d3d3d3")

' Apply different colors for data categorization
workSheet("A2:A11").Style.SetBackgroundColor("#E7F3FF") ' Light blue for January
workSheet("B2:B11").Style.SetBackgroundColor("#FFF2CC") ' Light yellow for February

' Highlight important cells with bold colors
workSheet("L12").Style.SetBackgroundColor("#FF0000") ' Red for totals
workSheet("L12").Style.Font.FontColor = "#FFFFFF" ' White text

' Create alternating row colors for better readability
For row As Integer = 2 To 11
	If row Mod 2 = 0 Then
		workSheet($"A{row}:L{row}").Style.SetBackgroundColor("#F2F2F2")
	End If
Next row

// Use IronXL built-in aggregations
decimal sum = workSheet["A2:A11"].Sum();
decimal avg = workSheet["B2:B11"].Avg();
decimal max = workSheet["C2:C11"].Max();
decimal min = workSheet["D2:D11"].Min();

// Assign value to cells
workSheet["A12"].Value = sum;
workSheet["B12"].Value = avg;
workSheet["C12"].Value = max;
workSheet["D12"].Value = min;

' Use IronXL built-in aggregations
Dim sum As Decimal = workSheet("A2:A11").Sum()
Dim avg As Decimal = workSheet("B2:B11").Avg()
Dim max As Decimal = workSheet("C2:C11").Max()
Dim min As Decimal = workSheet("D2:D11").Min()

' Assign value to cells
workSheet("A12").Value = sum
workSheet("B12").Value = avg
workSheet("C12").Value = max
workSheet("D12").Value = min

workSheet.SetPrintArea("A1:L12");
workSheet.PrintSetup.PrintOrientation = IronXL.Printing.PrintOrientation.Landscape;
workSheet.PrintSetup.PaperSize = IronXL.Printing.PaperSize.A4;

workSheet.SetPrintArea("A1:L12")
workSheet.PrintSetup.PrintOrientation = IronXL.Printing.PrintOrientation.Landscape
workSheet.PrintSetup.PaperSize = IronXL.Printing.PaperSize.A4

workBook.SaveAs("Budget.xlsx");

workBook.SaveAs("Budget.xlsx")

var dateCell = sheet["A2"];
dateCell.Value = DateTime.Today;
dateCell.FormatString = "yyyy-MM-dd";

var moneyCell = sheet["B2"];
moneyCell.Value = 1499.95m;
moneyCell.FormatString = "$#,##0.00";

Dim dateCell = sheet("A2")
dateCell.Value = DateTime.Today
dateCell.FormatString = "yyyy-MM-dd"

Dim moneyCell = sheet("B2")
moneyCell.Value = 1499.95D
moneyCell.FormatString = "$#,##0.00"

// CreateExcelBenchmark/Program.cs (excerpt)
IronXL.License.LicenseKey = Environment.GetEnvironmentVariable("IRONXL_LICENSE_KEY");

var sw = Stopwatch.StartNew();
var workbook = WorkBook.Create(ExcelFileFormat.XLSX);
var sheet = workbook.CreateWorkSheet("Data");
sheet["A1"].Value = "Id";
sheet["B1"].Value = "Name";
sheet["C1"].Value = "Amount";
for (int i = 0; i < 10_000; i++)
{
    int row = i + 2;
    sheet[$"A{row}"].Value = i + 1;
    sheet[$"B{row}"].Value = $"Item {i + 1}";
    sheet[$"C{row}"].Value = (i + 1) * 1.25m;
}
workbook.SaveAs("Generated.xlsx");
sw.Stop();
Console.WriteLine($"cold: {sw.Elapsed.TotalMilliseconds:F1} ms");

Imports System
Imports System.Diagnostics
Imports IronXL

Module Program
    Sub Main()
        License.LicenseKey = Environment.GetEnvironmentVariable("IRONXL_LICENSE_KEY")

        Dim sw As Stopwatch = Stopwatch.StartNew()
        Dim workbook As WorkBook = WorkBook.Create(ExcelFileFormat.XLSX)
        Dim sheet As WorkSheet = workbook.CreateWorkSheet("Data")
        sheet("A1").Value = "Id"
        sheet("B1").Value = "Name"
        sheet("C1").Value = "Amount"
        For i As Integer = 0 To 9999
            Dim row As Integer = i + 2
            sheet($"A{row}").Value = i + 1
            sheet($"B{row}").Value = $"Item {i + 1}"
            sheet($"C{row}").Value = (i + 1) * 1.25D
        Next
        workbook.SaveAs("Generated.xlsx")
        sw.Stop()
        Console.WriteLine($"cold: {sw.Elapsed.TotalMilliseconds:F1} ms")
    End Sub
End Module