IronXLを使用して C# で Excel ファイルを生成する方法

Install-Package IronXL.Excel
dotnet add package IronXL.Excel

using IronXL;
// Create an in-memory workbook
var workbook = WorkBook.Create();
Console.WriteLine("IronXL installed successfully!");

Imports IronXL

' Create an in-memory workbook
Dim workbook = WorkBook.Create()
Console.WriteLine("IronXL installed successfully!")

using IronXL;
// Create a new workbook (XLSX format by default)
WorkBook workbook = WorkBook.Create(ExcelFileFormat.XLSX);
// Add metadata
workbook.Metadata.Title = "Monthly Sales Report";
workbook.Metadata.Author = "Sales Department";
workbook.Metadata.Comments = "Generated using IronXL";
// Create a worksheet
WorkSheet worksheet = workbook.CreateWorkSheet("January Sales");
// Add header row
worksheet["A1"].Value = "Date";
worksheet["B1"].Value = "Product";
worksheet["C1"].Value = "Quantity";
worksheet["D1"].Value = "Revenue";
// Add data rows
worksheet["A2"].Value = new DateTime(2024, 1, 15);
worksheet["B2"].Value = "Widget Pro";
worksheet["C2"].Value = 100;
worksheet["D2"].Value = 2500.00;
// Save the workbook
workbook.SaveAs("FirstExcelFile.xlsx");

Imports IronXL

' Create a new workbook (XLSX format by default)
Dim workbook As WorkBook = WorkBook.Create(ExcelFileFormat.XLSX)

' Add metadata
workbook.Metadata.Title = "Monthly Sales Report"
workbook.Metadata.Author = "Sales Department"
workbook.Metadata.Comments = "Generated using IronXL"

' Create a worksheet
Dim worksheet As WorkSheet = workbook.CreateWorkSheet("January Sales")

' Add header row
worksheet("A1").Value = "Date"
worksheet("B1").Value = "Product"
worksheet("C1").Value = "Quantity"
worksheet("D1").Value = "Revenue"

' Add data rows
worksheet("A2").Value = New DateTime(2024, 1, 15)
worksheet("B2").Value = "Widget Pro"
worksheet("C2").Value = 100
worksheet("D2").Value = 2500.0

' Save the workbook
workbook.SaveAs("FirstExcelFile.xlsx")

using IronXL;
WorkBook workbook = WorkBook.Create(ExcelFileFormat.XLSX);
WorkSheet worksheet = workbook.CreateWorkSheet("Employees");
// Individual cell assignment
worksheet["A1"].Value = "Employee Name";
worksheet["A2"].Value = "John Smith";
worksheet["A3"].Value = "Jane Doe";
// Range assignment for multiple cells at once
worksheet["B1:B3"].Value = "Active";
// Using numeric indices (0-based row, 0-based column)
worksheet.SetCellValue(0, 2, "Department"); // C1
worksheet.SetCellValue(1, 2, "Sales");       // C2
worksheet.SetCellValue(2, 2, "Marketing");   // C3
// Array-based header population
string[] headers = { "ID", "Name", "Email", "Phone" };
for (int i = 0; i < headers.Length; i++)
{
    worksheet.SetCellValue(0, i, headers[i]);
}
// Working with different data types
worksheet["E1"].Value = "Salary";
worksheet["E2"].Value = 75000.50m;  // Decimal for currency
worksheet["E3"].Value = 82000.75m;
worksheet["F1"].Value = "Start Date";
worksheet["F2"].Value = new DateTime(2020, 3, 15);
worksheet["F3"].Value = new DateTime(2019, 7, 1);
worksheet["G1"].Value = "Full Time";
worksheet["G2"].Value = true;  // Boolean
worksheet["G3"].Value = true;
workbook.SaveAs("EmployeeData.xlsx");

Imports IronXL

Dim workbook As WorkBook = WorkBook.Create(ExcelFileFormat.XLSX)
Dim worksheet As WorkSheet = workbook.CreateWorkSheet("Employees")
' Individual cell assignment
worksheet("A1").Value = "Employee Name"
worksheet("A2").Value = "John Smith"
worksheet("A3").Value = "Jane Doe"
' Range assignment for multiple cells at once
worksheet("B1:B3").Value = "Active"
' Using numeric indices (0-based row, 0-based column)
worksheet.SetCellValue(0, 2, "Department") ' C1
worksheet.SetCellValue(1, 2, "Sales") ' C2
worksheet.SetCellValue(2, 2, "Marketing") ' C3
' Array-based header population
Dim headers As String() = {"ID", "Name", "Email", "Phone"}
For i As Integer = 0 To headers.Length - 1
    worksheet.SetCellValue(0, i, headers(i))
Next
' Working with different data types
worksheet("E1").Value = "Salary"
worksheet("E2").Value = 75000.5D ' Decimal for currency
worksheet("E3").Value = 82000.75D
worksheet("F1").Value = "Start Date"
worksheet("F2").Value = New DateTime(2020, 3, 15)
worksheet("F3").Value = New DateTime(2019, 7, 1)
worksheet("G1").Value = "Full Time"
worksheet("G2").Value = True ' Boolean
worksheet("G3").Value = True
workbook.SaveAs("EmployeeData.xlsx")

using IronXL;
WorkBook workbook = WorkBook.Create(ExcelFileFormat.XLSX);
WorkSheet worksheet = workbook.CreateWorkSheet("Employees");
// Header formatting
var headerRange = worksheet["A1:D1"];
headerRange.Style.Font.Bold = true;
headerRange.Style.Font.Height = 12;
headerRange.Style.SetBackgroundColor("#4472C4");
headerRange.Style.Font.Color = "#FFFFFF";
// Column width adjustment
worksheet.AutoSizeColumn(0); // Auto-fit column A
worksheet.GetColumn(1).Width = 20; // Set column B width
// Number formatting
var salaryColumn = worksheet["E2:E3"];
salaryColumn.FormatString = "$#,##0.00";
// Date formatting
var dateColumn = worksheet["F2:F3"];
dateColumn.FormatString = "MM/dd/yyyy";
// Cell borders
var dataRange = worksheet["A1:G3"];
dataRange.Style.TopBorder.Type = IronXL.Styles.BorderType.Thin;
dataRange.Style.BottomBorder.Type = IronXL.Styles.BorderType.Thin;
dataRange.Style.LeftBorder.Type = IronXL.Styles.BorderType.Thin;
dataRange.Style.RightBorder.Type = IronXL.Styles.BorderType.Thin;
dataRange.Style.TopBorder.Color = "#000000";
dataRange.Style.BottomBorder.Color = "#000000";
// Text alignment
worksheet["A1:G1"].Style.HorizontalAlignment = IronXL.Styles.HorizontalAlignment.Center;
// Alternating row colors for readability (banded rows)
for (int row = 2; row <= 10; row++)
{
    if (row % 2 == 0)
    {
        worksheet[$"A{row}:G{row}"].Style.SetBackgroundColor("#F2F2F2");
    }
}
workbook.SaveAs("FormattedReport.xlsx");

Imports IronXL

Dim workbook As WorkBook = WorkBook.Create(ExcelFileFormat.XLSX)
Dim worksheet As WorkSheet = workbook.CreateWorkSheet("Employees")

' Header formatting
Dim headerRange = worksheet("A1:D1")
headerRange.Style.Font.Bold = True
headerRange.Style.Font.Height = 12
headerRange.Style.SetBackgroundColor("#4472C4")
headerRange.Style.Font.Color = "#FFFFFF"

' Column width adjustment
worksheet.AutoSizeColumn(0) ' Auto-fit column A
worksheet.GetColumn(1).Width = 20 ' Set column B width

' Number formatting
Dim salaryColumn = worksheet("E2:E3")
salaryColumn.FormatString = "$#,##0.00"

' Date formatting
Dim dateColumn = worksheet("F2:F3")
dateColumn.FormatString = "MM/dd/yyyy"

' Cell borders
Dim dataRange = worksheet("A1:G3")
dataRange.Style.TopBorder.Type = IronXL.Styles.BorderType.Thin
dataRange.Style.BottomBorder.Type = IronXL.Styles.BorderType.Thin
dataRange.Style.LeftBorder.Type = IronXL.Styles.BorderType.Thin
dataRange.Style.RightBorder.Type = IronXL.Styles.BorderType.Thin
dataRange.Style.TopBorder.Color = "#000000"
dataRange.Style.BottomBorder.Color = "#000000"

' Text alignment
worksheet("A1:G1").Style.HorizontalAlignment = IronXL.Styles.HorizontalAlignment.Center

' Alternating row colors for readability (banded rows)
For row As Integer = 2 To 10
    If row Mod 2 = 0 Then
        worksheet($"A{row}:G{row}").Style.SetBackgroundColor("#F2F2F2")
    End If
Next

workbook.SaveAs("FormattedReport.xlsx")

using IronXL;
var workbook = WorkBook.Create();
// Create a budget worksheet
WorkSheet budget = workbook.CreateWorkSheet("Q1 Budget");
// Headers
budget["A1"].Value = "Category";
budget["B1"].Value = "January";
budget["C1"].Value = "February";
budget["D1"].Value = "March";
budget["E1"].Value = "Q1 Total";
// Budget categories and values
string[] categories = { "Salaries", "Marketing", "Operations", "Equipment", "Training" };
decimal[,] monthlyBudgets = {
    { 50000, 52000, 51000 },
    { 15000, 18000, 20000 },
    { 8000, 8500, 9000 },
    { 12000, 5000, 7000 },
    { 3000, 3500, 4000 }
};
// Populate data and add row total formulas
for (int i = 0; i < categories.Length; i++)
{
    budget[$"A{i + 2}"].Value = categories[i];
    budget[$"B{i + 2}"].Value = monthlyBudgets[i, 0];
    budget[$"C{i + 2}"].Value = monthlyBudgets[i, 1];
    budget[$"D{i + 2}"].Value = monthlyBudgets[i, 2];
    budget[$"E{i + 2}"].Formula = $"=SUM(B{i + 2}:D{i + 2})";
}
// Monthly totals row
budget["A7"].Value = "Monthly Total";
budget["B7"].Formula = "=SUM(B2:B6)";
budget["C7"].Formula = "=SUM(C2:C6)";
budget["D7"].Formula = "=SUM(D2:D6)";
budget["E7"].Formula = "=SUM(E2:E6)";
// Calculate percentages
budget["A9"].Value = "Marketing %";
budget["B9"].Formula = "=B3/B7*100";
// Average calculation
budget["A10"].Value = "Average Spending";
budget["B10"].Formula = "=AVERAGE(B2:B6)";
// Evaluate all formulas before saving
workbook.EvaluateAll();
workbook.SaveAs("Budget.xlsx");

Imports IronXL

Dim workbook = WorkBook.Create()
' Create a budget worksheet
Dim budget As WorkSheet = workbook.CreateWorkSheet("Q1 Budget")
' Headers
budget("A1").Value = "Category"
budget("B1").Value = "January"
budget("C1").Value = "February"
budget("D1").Value = "March"
budget("E1").Value = "Q1 Total"
' Budget categories and values
Dim categories As String() = {"Salaries", "Marketing", "Operations", "Equipment", "Training"}
Dim monthlyBudgets As Decimal(,) = {
    {50000, 52000, 51000},
    {15000, 18000, 20000},
    {8000, 8500, 9000},
    {12000, 5000, 7000},
    {3000, 3500, 4000}
}
' Populate data and add row total formulas
For i As Integer = 0 To categories.Length - 1
    budget($"A{i + 2}").Value = categories(i)
    budget($"B{i + 2}").Value = monthlyBudgets(i, 0)
    budget($"C{i + 2}").Value = monthlyBudgets(i, 1)
    budget($"D{i + 2}").Value = monthlyBudgets(i, 2)
    budget($"E{i + 2}").Formula = $"=SUM(B{i + 2}:D{i + 2})"
Next
' Monthly totals row
budget("A7").Value = "Monthly Total"
budget("B7").Formula = "=SUM(B2:B6)"
budget("C7").Formula = "=SUM(C2:C6)"
budget("D7").Formula = "=SUM(D2:D6)"
budget("E7").Formula = "=SUM(E2:E6)"
' Calculate percentages
budget("A9").Value = "Marketing %"
budget("B9").Formula = "=B3/B7*100"
' Average calculation
budget("A10").Value = "Average Spending"
budget("B10").Formula = "=AVERAGE(B2:B6)"
' Evaluate all formulas before saving
workbook.EvaluateAll()
workbook.SaveAs("Budget.xlsx")

using System.Data;
using IronXL;

// Simulate database retrieval (replace with actual database code)
DataTable GetSalesData()
{
    DataTable dt = new DataTable("Sales");
    dt.Columns.Add("OrderID", typeof(int));
    dt.Columns.Add("CustomerName", typeof(string));
    dt.Columns.Add("Product", typeof(string));
    dt.Columns.Add("Quantity", typeof(int));
    dt.Columns.Add("UnitPrice", typeof(decimal));
    dt.Columns.Add("OrderDate", typeof(DateTime));
    dt.Rows.Add(1001, "ABC Corp", "Widget Pro", 50, 25.99m, DateTime.Now.AddDays(-5));
    dt.Rows.Add(1002, "XYZ Ltd", "Widget Basic", 100, 15.99m, DateTime.Now.AddDays(-4));
    dt.Rows.Add(1003, "ABC Corp", "Widget Premium", 25, 45.99m, DateTime.Now.AddDays(-3));
    dt.Rows.Add(1004, "Tech Solutions", "Widget Pro", 75, 25.99m, DateTime.Now.AddDays(-2));
    dt.Rows.Add(1005, "XYZ Ltd", "Widget Premium", 30, 45.99m, DateTime.Now.AddDays(-1));
    return dt;
}

// Export to Excel
WorkBook reportWorkbook = WorkBook.Create();
WorkSheet reportSheet = reportWorkbook.CreateWorkSheet("Sales Report");
DataTable salesData = GetSalesData();

// Title row
reportSheet["A1"].Value = "Order Report - " + DateTime.Now.ToString("MMMM yyyy");
reportSheet.Merge("A1:F1");
reportSheet["A1"].Style.Font.Bold = true;
reportSheet["A1"].Style.Font.Height = 14;

// Headers
int headerRow = 3;
for (int col = 0; col < salesData.Columns.Count; col++)
{
    reportSheet.SetCellValue(headerRow - 1, col, salesData.Columns[col].ColumnName);
}
var headers = reportSheet[$"A{headerRow}:F{headerRow}"];
headers.Style.Font.Bold = true;
headers.Style.SetBackgroundColor("#D9E1F2");

// Data rows
for (int row = 0; row < salesData.Rows.Count; row++)
{
    for (int col = 0; col < salesData.Columns.Count; col++)
    {
        reportSheet.SetCellValue(row + headerRow, col, salesData.Rows[row][col]);
    }
    reportSheet[$"G{row + headerRow + 1}"].Formula = $"=D{row + headerRow + 1}*E{row + headerRow + 1}";
}

// Total header
reportSheet["G3"].Value = "Total";
reportSheet["G3"].Style.Font.Bold = true;
reportSheet["G3"].Style.SetBackgroundColor("#D9E1F2");
// Format currency and date columns
reportSheet[$"E{headerRow + 1}:E{headerRow + salesData.Rows.Count}"].FormatString = "$#,##0.00";
reportSheet[$"G{headerRow + 1}:G{headerRow + salesData.Rows.Count}"].FormatString = "$#,##0.00";
reportSheet[$"F{headerRow + 1}:F{headerRow + salesData.Rows.Count}"].FormatString = "MM/dd/yyyy";

// Summary section
int summaryRow = headerRow + salesData.Rows.Count + 2;
reportSheet[$"A{summaryRow}"].Value = "Summary";
reportSheet[$"A{summaryRow}"].Style.Font.Bold = true;
reportSheet[$"A{summaryRow + 1}"].Value = "Total Orders:";
reportSheet[$"B{summaryRow + 1}"].Formula = $"=COUNTA(A{headerRow + 1}:A{headerRow + salesData.Rows.Count})";
reportSheet[$"A{summaryRow + 2}"].Value = "Total Revenue:";
reportSheet[$"B{summaryRow + 2}"].Formula = $"=SUM(G{headerRow + 1}:G{headerRow + salesData.Rows.Count})";
reportSheet[$"B{summaryRow + 2}"].FormatString = "$#,##0.00";

for (int col = 0; col <= 6; col++) { reportSheet.AutoSizeColumn(col); }
reportWorkbook.EvaluateAll();
reportWorkbook.SaveAs("DatabaseExport.xlsx");

Imports System.Data
Imports IronXL

' Simulate database retrieval (replace with actual database code)
Function GetSalesData() As DataTable
    Dim dt As New DataTable("Sales")
    dt.Columns.Add("OrderID", GetType(Integer))
    dt.Columns.Add("CustomerName", GetType(String))
    dt.Columns.Add("Product", GetType(String))
    dt.Columns.Add("Quantity", GetType(Integer))
    dt.Columns.Add("UnitPrice", GetType(Decimal))
    dt.Columns.Add("OrderDate", GetType(DateTime))
    dt.Rows.Add(1001, "ABC Corp", "Widget Pro", 50, 25.99D, DateTime.Now.AddDays(-5))
    dt.Rows.Add(1002, "XYZ Ltd", "Widget Basic", 100, 15.99D, DateTime.Now.AddDays(-4))
    dt.Rows.Add(1003, "ABC Corp", "Widget Premium", 25, 45.99D, DateTime.Now.AddDays(-3))
    dt.Rows.Add(1004, "Tech Solutions", "Widget Pro", 75, 25.99D, DateTime.Now.AddDays(-2))
    dt.Rows.Add(1005, "XYZ Ltd", "Widget Premium", 30, 45.99D, DateTime.Now.AddDays(-1))
    Return dt
End Function

' Export to Excel
Dim reportWorkbook As WorkBook = WorkBook.Create()
Dim reportSheet As WorkSheet = reportWorkbook.CreateWorkSheet("Sales Report")
Dim salesData As DataTable = GetSalesData()

' Title row
reportSheet("A1").Value = "Order Report - " & DateTime.Now.ToString("MMMM yyyy")
reportSheet.Merge("A1:F1")
reportSheet("A1").Style.Font.Bold = True
reportSheet("A1").Style.Font.Height = 14

' Headers
Dim headerRow As Integer = 3
For col As Integer = 0 To salesData.Columns.Count - 1
    reportSheet.SetCellValue(headerRow - 1, col, salesData.Columns(col).ColumnName)
Next
Dim headers = reportSheet($"A{headerRow}:F{headerRow}")
headers.Style.Font.Bold = True
headers.Style.SetBackgroundColor("#D9E1F2")

' Data rows
For row As Integer = 0 To salesData.Rows.Count - 1
    For col As Integer = 0 To salesData.Columns.Count - 1
        reportSheet.SetCellValue(row + headerRow, col, salesData.Rows(row)(col))
    Next
    reportSheet($"G{row + headerRow + 1}").Formula = $"=D{row + headerRow + 1}*E{row + headerRow + 1}"
Next

' Total header
reportSheet("G3").Value = "Total"
reportSheet("G3").Style.Font.Bold = True
reportSheet("G3").Style.SetBackgroundColor("#D9E1F2")

' Format currency and date columns
reportSheet($"E{headerRow + 1}:E{headerRow + salesData.Rows.Count}").FormatString = "$#,##0.00"
reportSheet($"G{headerRow + 1}:G{headerRow + salesData.Rows.Count}").FormatString = "$#,##0.00"
reportSheet($"F{headerRow + 1}:F{headerRow + salesData.Rows.Count}").FormatString = "MM/dd/yyyy"

' Summary section
Dim summaryRow As Integer = headerRow + salesData.Rows.Count + 2
reportSheet($"A{summaryRow}").Value = "Summary"
reportSheet($"A{summaryRow}").Style.Font.Bold = True
reportSheet($"A{summaryRow + 1}").Value = "Total Orders:"
reportSheet($"B{summaryRow + 1}").Formula = $"=COUNTA(A{headerRow + 1}:A{headerRow + salesData.Rows.Count})"
reportSheet($"A{summaryRow + 2}").Value = "Total Revenue:"
reportSheet($"B{summaryRow + 2}").Formula = $"=SUM(G{headerRow + 1}:G{headerRow + salesData.Rows.Count})"
reportSheet($"B{summaryRow + 2}").FormatString = "$#,##0.00"

For col As Integer = 0 To 6
    reportSheet.AutoSizeColumn(col)
Next
reportWorkbook.EvaluateAll()
reportWorkbook.SaveAs("DatabaseExport.xlsx")

using IronXL;
WorkBook companyReport = WorkBook.Create();
// Create department sheets
WorkSheet salesSheet = companyReport.CreateWorkSheet("Sales");
WorkSheet inventorySheet = companyReport.CreateWorkSheet("Inventory");
WorkSheet summarySheet = companyReport.CreateWorkSheet("Summary");

// Populate Sales sheet
salesSheet["A1"].Value = "Sales Dashboard";
salesSheet["A3"].Value = "Region";
salesSheet["B3"].Value = "Q1 Sales";
salesSheet["C3"].Value = "Q2 Sales";
string[] regions = { "North", "South", "East", "West" };
decimal[] q1Sales = { 250000, 180000, 220000, 195000 };
decimal[] q2Sales = { 275000, 195000, 240000, 210000 };
for (int i = 0; i < regions.Length; i++)
{
    salesSheet[$"A{i + 4}"].Value = regions[i];
    salesSheet[$"B{i + 4}"].Value = q1Sales[i];
    salesSheet[$"C{i + 4}"].Value = q2Sales[i];
}

// Populate Inventory sheet
inventorySheet["A1"].Value = "Inventory Status";
string[] products = { "Widget A", "Widget B", "Widget C" };
int[] stock = { 150, 45, 200 };
int[] reorderPoint = { 100, 50, 75 };
for (int i = 0; i < products.Length; i++)
{
    inventorySheet[$"A{i + 4}"].Value = products[i];
    inventorySheet[$"B{i + 4}"].Value = stock[i];
    inventorySheet[$"C{i + 4}"].Value = reorderPoint[i];
    string status = stock[i] <= reorderPoint[i] ? "REORDER" : "OK";
    inventorySheet[$"D{i + 4}"].Value = status;
    if (status == "REORDER")
        inventorySheet[$"D{i + 4}"].Style.Font.Color = "#FF0000";
}

// Summary sheet with cross-sheet formulas
summarySheet["A1"].Value = "Company Overview";
summarySheet["A4"].Value = "Total Q1 Sales";
summarySheet["B4"].Formula = "=SUM(Sales!B4:B7)";
summarySheet["A5"].Value = "Total Q2 Sales";
summarySheet["B5"].Formula = "=SUM(Sales!C4:C7)";
summarySheet["A6"].Value = "Products Need Reorder";
summarySheet["B6"].Formula = "=COUNTIF(Inventory!D4:D6,\"REORDER\")";

// Apply consistent formatting across all sheets
foreach (WorkSheet sheet in companyReport.WorkSheets)
{
    sheet["A1"].Style.Font.Bold = true;
    sheet["A1"].Style.Font.Height = 14;
}
companyReport.SaveAs("CompanyReport.xlsx");

Imports IronXL

Dim companyReport As WorkBook = WorkBook.Create()
' Create department sheets
Dim salesSheet As WorkSheet = companyReport.CreateWorkSheet("Sales")
Dim inventorySheet As WorkSheet = companyReport.CreateWorkSheet("Inventory")
Dim summarySheet As WorkSheet = companyReport.CreateWorkSheet("Summary")

' Populate Sales sheet
salesSheet("A1").Value = "Sales Dashboard"
salesSheet("A3").Value = "Region"
salesSheet("B3").Value = "Q1 Sales"
salesSheet("C3").Value = "Q2 Sales"
Dim regions As String() = {"North", "South", "East", "West"}
Dim q1Sales As Decimal() = {250000, 180000, 220000, 195000}
Dim q2Sales As Decimal() = {275000, 195000, 240000, 210000}
For i As Integer = 0 To regions.Length - 1
    salesSheet($"A{i + 4}").Value = regions(i)
    salesSheet($"B{i + 4}").Value = q1Sales(i)
    salesSheet($"C{i + 4}").Value = q2Sales(i)
Next

' Populate Inventory sheet
inventorySheet("A1").Value = "Inventory Status"
Dim products As String() = {"Widget A", "Widget B", "Widget C"}
Dim stock As Integer() = {150, 45, 200}
Dim reorderPoint As Integer() = {100, 50, 75}
For i As Integer = 0 To products.Length - 1
    inventorySheet($"A{i + 4}").Value = products(i)
    inventorySheet($"B{i + 4}").Value = stock(i)
    inventorySheet($"C{i + 4}").Value = reorderPoint(i)
    Dim status As String = If(stock(i) <= reorderPoint(i), "REORDER", "OK")
    inventorySheet($"D{i + 4}").Value = status
    If status = "REORDER" Then
        inventorySheet($"D{i + 4}").Style.Font.Color = "#FF0000"
    End If
Next

' Summary sheet with cross-sheet formulas
summarySheet("A1").Value = "Company Overview"
summarySheet("A4").Value = "Total Q1 Sales"
summarySheet("B4").Formula = "=SUM(Sales!B4:B7)"
summarySheet("A5").Value = "Total Q2 Sales"
summarySheet("B5").Formula = "=SUM(Sales!C4:C7)"
summarySheet("A6").Value = "Products Need Reorder"
summarySheet("B6").Formula = "=COUNTIF(Inventory!D4:D6,""REORDER"")"

' Apply consistent formatting across all sheets
For Each sheet As WorkSheet In companyReport.WorkSheets
    sheet("A1").Style.Font.Bold = True
    sheet("A1").Style.Font.Height = 14
Next

companyReport.SaveAs("CompanyReport.xlsx")

using IronXL;
WorkBook workbook = WorkBook.Create();
WorkSheet sheet = workbook.CreateWorkSheet("Data");
int rowsPerBatch = 1000;
int currentRow = 2;
sheet["A1"].Value = "ID";
sheet["B1"].Value = "Name";
sheet["C1"].Value = "Value";
// Process records in manageable batches
foreach (var batch in GetDataInBatches(rowsPerBatch))
{
    foreach (var record in batch)
    {
        sheet[$"A{currentRow}"].Value = record.Id;
        sheet[$"B{currentRow}"].Value = record.Name;
        sheet[$"C{currentRow}"].Value = record.Value;
        currentRow++;
    }
}
workbook.SaveAs("LargeDataset.xlsx");

Imports IronXL

Dim workbook As WorkBook = WorkBook.Create()
Dim sheet As WorkSheet = workbook.CreateWorkSheet("Data")
Dim rowsPerBatch As Integer = 1000
Dim currentRow As Integer = 2
sheet("A1").Value = "ID"
sheet("B1").Value = "Name"
sheet("C1").Value = "Value"
' Process records in manageable batches
For Each batch In GetDataInBatches(rowsPerBatch)
    For Each record In batch
        sheet($"A{currentRow}").Value = record.Id
        sheet($"B{currentRow}").Value = record.Name
        sheet($"C{currentRow}").Value = record.Value
        currentRow += 1
    Next
Next
workbook.SaveAs("LargeDataset.xlsx")

// ASP.NET Core controller action with error handling
IActionResult DownloadExcel()
{
    try
    {
        WorkBook workbook = WorkBook.Create();
        WorkSheet sheet = workbook.CreateWorkSheet("Report");
        sheet["A1"].Value = "Report Data";
        // Populate report data here...
        var stream = new MemoryStream();
        workbook.SaveAs(stream);
        stream.Position = 0;
        return File(stream,
            "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
            "report.xlsx");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Excel generation failed: {ex.Message}");
        return StatusCode(500, "Failed to generate Excel file.");
    }
}

Imports System
Imports System.IO
Imports Microsoft.AspNetCore.Mvc

Public Class YourController
    Inherits Controller

    Public Function DownloadExcel() As IActionResult
        Try
            Dim workbook As WorkBook = WorkBook.Create()
            Dim sheet As WorkSheet = workbook.CreateWorkSheet("Report")
            sheet("A1").Value = "Report Data"
            ' Populate report data here...
            Dim stream As New MemoryStream()
            workbook.SaveAs(stream)
            stream.Position = 0
            Return File(stream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "report.xlsx")
        Catch ex As Exception
            Console.WriteLine($"Excel generation failed: {ex.Message}")
            Return StatusCode(500, "Failed to generate Excel file.")
        End Try
    End Function
End Class