IronXL Tutorials How to Read Excel Files in C# How to Read Excel Files in C# Without Interop: Complete Developer Guide ByJacob Mellor May 26, 2019 Updated July 28, 2025 Share: Master Excel file manipulation in C# using IronXL—the powerful .NET library that reads, validates, and exports spreadsheet data without requiring Microsoft Office installation. This comprehensive tutorial demonstrates practical Excel operations including data validation, database conversion, and REST API integration. View the IronXL YouTube Playlist How Do I Set Up IronXL to Read Excel Files in C#? Setting up IronXL for reading Excel files in your C# project takes just minutes. The library supports both .XLS and .XLSX formats, making it versatile for any Excel-related task. Follow these steps to get started: Download the C# Library to read Excel files Load and read Excel workbooks using WorkBook.Load() Access worksheets with the GetWorkSheet() method Read cell values using intuitive syntax like sheet["A1"].Value Validate and process spreadsheet data programmatically Export data to databases using Entity Framework IronXL excels at reading and editing Microsoft Excel documents with C#. The library operates independently—it neither requires Microsoft Excel nor Interop to function. In fact, IronXL provides a faster and more intuitive API than Microsoft.Office.Interop.Excel. IronXL Includes: Dedicated product support from our .NET engineers Easy installation via Microsoft Visual Studio Free trial test for development. Licenses from $749 Reading and creating Excel files in C# and VB.NET becomes straightforward using the IronXL software library. Reading .XLS and .XLSX Excel Files Using IronXL Here's the essential workflow for reading Excel files using IronXL: Install the IronXL Excel Library via NuGet package or download the .NET Excel DLL Use the WorkBook.Load() method to read any XLS, XLSX, or CSV document Access cell values using intuitive syntax: sheet["A11"].DecimalValue using IronXL; using System; using System.Linq; // Load Excel workbook from file path WorkBook workBook = WorkBook.Load("test.xlsx"); // Access the first worksheet using LINQ WorkSheet workSheet = workBook.WorkSheets.First(); // Read integer value from cell A2 int cellValue = workSheet["A2"].IntValue; Console.WriteLine($"Cell A2 value: {cellValue}"); // Iterate through a range of cells foreach (var cell in workSheet["A2:A10"]) { Console.WriteLine($"Cell {cell.AddressString} = '{cell.Text}'"); } // Advanced Operations with LINQ // Calculate sum using built-in Sum() method decimal sum = workSheet["A2:A10"].Sum(); // Find maximum value using LINQ decimal max = workSheet["A2:A10"].Max(c => c.DecimalValue); // Output calculated results Console.WriteLine($"Sum of A2:A10: {sum}"); Console.WriteLine($"Maximum value: {max}"); using IronXL; using System; using System.Linq; // Load Excel workbook from file path WorkBook workBook = WorkBook.Load("test.xlsx"); // Access the first worksheet using LINQ WorkSheet workSheet = workBook.WorkSheets.First(); // Read integer value from cell A2 int cellValue = workSheet["A2"].IntValue; Console.WriteLine($"Cell A2 value: {cellValue}"); // Iterate through a range of cells foreach (var cell in workSheet["A2:A10"]) { Console.WriteLine($"Cell {cell.AddressString} = '{cell.Text}'"); } // Advanced Operations with LINQ // Calculate sum using built-in Sum() method decimal sum = workSheet["A2:A10"].Sum(); // Find maximum value using LINQ decimal max = workSheet["A2:A10"].Max(c => c.DecimalValue); // Output calculated results Console.WriteLine($"Sum of A2:A10: {sum}"); Console.WriteLine($"Maximum value: {max}"); Imports IronXL Imports System Imports System.Linq ' Load Excel workbook from file path Private workBook As WorkBook = WorkBook.Load("test.xlsx") ' Access the first worksheet using LINQ Private workSheet As WorkSheet = workBook.WorkSheets.First() ' Read integer value from cell A2 Private cellValue As Integer = workSheet("A2").IntValue Console.WriteLine($"Cell A2 value: {cellValue}") ' Iterate through a range of cells For Each cell In workSheet("A2:A10") Console.WriteLine($"Cell {cell.AddressString} = '{cell.Text}'") Next cell ' Advanced Operations with LINQ ' Calculate sum using built-in Sum() method Dim sum As Decimal = workSheet("A2:A10").Sum() ' Find maximum value using LINQ Dim max As Decimal = workSheet("A2:A10").Max(Function(c) c.DecimalValue) ' Output calculated results Console.WriteLine($"Sum of A2:A10: {sum}") Console.WriteLine($"Maximum value: {max}") $vbLabelText $csharpLabel This code demonstrates several key IronXL features: loading workbooks, accessing cells by address, iterating through ranges, and performing calculations. The WorkBook.Load() method intelligently detects file formats, while the range syntax ["A2:A10"] provides Excel-like cell selection. LINQ integration enables powerful data queries and aggregations on cell collections. The code examples in this tutorial work with three sample Excel spreadsheets that showcase different data scenarios: Sample Excel files (GDP.xlsx, People.xlsx, and PopulationByState.xlsx) used throughout this tutorial for demonstrating various IronXL operations. How Can I Install the IronXL C# Library? Start using IronXL in your project today with a free trial. First Step: Start for Free Installing the IronXL.Excel library adds comprehensive Excel functionality to your .NET framework projects. Choose between NuGet installation or manual DLL integration. Installing the IronXL NuGet Package In Visual Studio, right-click on your project and select "Manage NuGet Packages..." Search for "IronXL.Excel" in the Browse tab Click the Install button to add IronXL to your project Installing IronXL through Visual Studio's NuGet Package Manager provides automatic dependency management. Alternatively, install IronXL using the Package Manager Console: Open the Package Manager Console (Tools → NuGet Package Manager → Package Manager Console) Run the installation command: :InstallCmd :InstallCmd SHELL You can also view the package details on the NuGet website. Manual Installation For manual installation, download the IronXL .NET Excel DLL and reference it directly in your Visual Studio project. How Do I Load and Read an Excel Workbook? The WorkBook class represents an entire Excel file. Load Excel files using the WorkBook.Load() method, which accepts file paths for XLS, XLSX, CSV, and TSV formats. using System; using IronXL; // Initialize WorkBook variable WorkBook workBook = null; try { // Load Excel file from specified path workBook = WorkBook.Load(@"Spreadsheets\GDP.xlsx"); Console.WriteLine("Workbook loaded successfully."); // Access specific worksheet by name WorkSheet sheet = workBook.GetWorkSheet("Sheet1"); // Read and display cell value string cellValue = sheet["A1"].StringValue; Console.WriteLine($"Cell A1 contains: {cellValue}"); // Perform additional operations // Count non-empty cells in column A int rowCount = sheet["A:A"].Count(cell => !cell.IsEmpty); Console.WriteLine($"Column A has {rowCount} non-empty cells"); } catch (Exception ex) { Console.WriteLine($"Error loading workbook: {ex.Message}"); } using System; using IronXL; // Initialize WorkBook variable WorkBook workBook = null; try { // Load Excel file from specified path workBook = WorkBook.Load(@"Spreadsheets\GDP.xlsx"); Console.WriteLine("Workbook loaded successfully."); // Access specific worksheet by name WorkSheet sheet = workBook.GetWorkSheet("Sheet1"); // Read and display cell value string cellValue = sheet["A1"].StringValue; Console.WriteLine($"Cell A1 contains: {cellValue}"); // Perform additional operations // Count non-empty cells in column A int rowCount = sheet["A:A"].Count(cell => !cell.IsEmpty); Console.WriteLine($"Column A has {rowCount} non-empty cells"); } catch (Exception ex) { Console.WriteLine($"Error loading workbook: {ex.Message}"); } Imports System Imports IronXL ' Initialize WorkBook variable Private workBook As WorkBook = Nothing Try ' Load Excel file from specified path workBook = WorkBook.Load("Spreadsheets\GDP.xlsx") Console.WriteLine("Workbook loaded successfully.") ' Access specific worksheet by name Dim sheet As WorkSheet = workBook.GetWorkSheet("Sheet1") ' Read and display cell value Dim cellValue As String = sheet("A1").StringValue Console.WriteLine($"Cell A1 contains: {cellValue}") ' Perform additional operations ' Count non-empty cells in column A Dim rowCount As Integer = sheet("A:A").Count(Function(cell) Not cell.IsEmpty) Console.WriteLine($"Column A has {rowCount} non-empty cells") Catch ex As Exception Console.WriteLine($"Error loading workbook: {ex.Message}") End Try $vbLabelText $csharpLabel Each WorkBook contains multiple WorkSheet objects representing individual Excel sheets. Access worksheets by name using GetWorkSheet(): // Validate workbook is loaded if (workBook == null) { throw new InvalidOperationException("Workbook must be loaded first"); } // Get worksheet by name WorkSheet workSheet = workBook.GetWorkSheet("GDPByCountry"); // Handle case where worksheet doesn't exist if (workSheet == null) { Console.WriteLine("Worksheet 'GDPByCountry' not found"); // List available worksheets foreach (var sheet in workBook.WorkSheets) { Console.WriteLine($"Available: {sheet.Name}"); } } else { Console.WriteLine($"Successfully loaded worksheet: {workSheet.Name}"); } // Validate workbook is loaded if (workBook == null) { throw new InvalidOperationException("Workbook must be loaded first"); } // Get worksheet by name WorkSheet workSheet = workBook.GetWorkSheet("GDPByCountry"); // Handle case where worksheet doesn't exist if (workSheet == null) { Console.WriteLine("Worksheet 'GDPByCountry' not found"); // List available worksheets foreach (var sheet in workBook.WorkSheets) { Console.WriteLine($"Available: {sheet.Name}"); } } else { Console.WriteLine($"Successfully loaded worksheet: {workSheet.Name}"); } ' Validate workbook is loaded If workBook Is Nothing Then Throw New InvalidOperationException("Workbook must be loaded first") End If ' Get worksheet by name Dim workSheet As WorkSheet = workBook.GetWorkSheet("GDPByCountry") ' Handle case where worksheet doesn't exist If workSheet Is Nothing Then Console.WriteLine("Worksheet 'GDPByCountry' not found") ' List available worksheets For Each sheet In workBook.WorkSheets Console.WriteLine($"Available: {sheet.Name}") Next sheet Else Console.WriteLine($"Successfully loaded worksheet: {workSheet.Name}") End If $vbLabelText $csharpLabel How Do I Create New Excel Documents in C#? Create new Excel documents by constructing a WorkBook object with your desired file format. IronXL supports both modern XLSX and legacy XLS formats. using IronXL; // Create new XLSX workbook (recommended format) WorkBook workBook = WorkBook.Create(ExcelFileFormat.XLSX); // Set workbook metadata workBook.Metadata.Author = "Your Application"; workBook.Metadata.Comments = "Generated by IronXL"; // Create new XLS workbook for legacy support WorkBook legacyWorkBook = WorkBook.Create(ExcelFileFormat.XLS); // Save the workbook workBook.SaveAs("NewDocument.xlsx"); using IronXL; // Create new XLSX workbook (recommended format) WorkBook workBook = WorkBook.Create(ExcelFileFormat.XLSX); // Set workbook metadata workBook.Metadata.Author = "Your Application"; workBook.Metadata.Comments = "Generated by IronXL"; // Create new XLS workbook for legacy support WorkBook legacyWorkBook = WorkBook.Create(ExcelFileFormat.XLS); // Save the workbook workBook.SaveAs("NewDocument.xlsx"); Imports IronXL ' Create new XLSX workbook (recommended format) Private workBook As WorkBook = WorkBook.Create(ExcelFileFormat.XLSX) ' Set workbook metadata workBook.Metadata.Author = "Your Application" workBook.Metadata.Comments = "Generated by IronXL" ' Create new XLS workbook for legacy support Dim legacyWorkBook As WorkBook = WorkBook.Create(ExcelFileFormat.XLS) ' Save the workbook workBook.SaveAs("NewDocument.xlsx") $vbLabelText $csharpLabel Note: Use ExcelFileFormat.XLS only when compatibility with Excel 2003 and earlier is required. How Can I Add Worksheets to an Excel Document? An IronXL WorkBook contains a collection of worksheets. Understanding this structure helps when building multi-sheet Excel files. Visual representation of the WorkBook structure containing multiple WorkSheet objects in IronXL. Create new worksheets using CreateWorkSheet(): // Create multiple worksheets with descriptive names WorkSheet summarySheet = workBook.CreateWorkSheet("Summary"); WorkSheet dataSheet = workBook.CreateWorkSheet("RawData"); WorkSheet chartSheet = workBook.CreateWorkSheet("Charts"); // Set the active worksheet workBook.SetActiveTab(0); // Makes "Summary" the active sheet // Access default worksheet (first sheet) WorkSheet defaultSheet = workBook.DefaultWorkSheet; // Create multiple worksheets with descriptive names WorkSheet summarySheet = workBook.CreateWorkSheet("Summary"); WorkSheet dataSheet = workBook.CreateWorkSheet("RawData"); WorkSheet chartSheet = workBook.CreateWorkSheet("Charts"); // Set the active worksheet workBook.SetActiveTab(0); // Makes "Summary" the active sheet // Access default worksheet (first sheet) WorkSheet defaultSheet = workBook.DefaultWorkSheet; ' Create multiple worksheets with descriptive names Dim summarySheet As WorkSheet = workBook.CreateWorkSheet("Summary") Dim dataSheet As WorkSheet = workBook.CreateWorkSheet("RawData") Dim chartSheet As WorkSheet = workBook.CreateWorkSheet("Charts") ' Set the active worksheet workBook.SetActiveTab(0) ' Makes "Summary" the active sheet ' Access default worksheet (first sheet) Dim defaultSheet As WorkSheet = workBook.DefaultWorkSheet $vbLabelText $csharpLabel How Do I Read and Edit Cell Values? Read and Edit a Single Cell Access individual cells through the worksheet's indexer property. IronXL's Cell class provides strongly-typed value properties. using IronXL; // Load workbook and get worksheet WorkBook workBook = WorkBook.Load("test.xlsx"); WorkSheet workSheet = workBook.DefaultWorkSheet; // Access cell B1 IronXL.Cell cell = workSheet["B1"]; // Read cell value with type safety string textValue = cell.StringValue; int intValue = cell.IntValue; decimal decimalValue = cell.DecimalValue; DateTime? dateValue = cell.DateTimeValue; // Check cell data type if (cell.IsNumeric) { Console.WriteLine($"Numeric value: {cell.DecimalValue}"); } else if (cell.IsText) { Console.WriteLine($"Text value: {cell.StringValue}"); } using IronXL; // Load workbook and get worksheet WorkBook workBook = WorkBook.Load("test.xlsx"); WorkSheet workSheet = workBook.DefaultWorkSheet; // Access cell B1 IronXL.Cell cell = workSheet["B1"]; // Read cell value with type safety string textValue = cell.StringValue; int intValue = cell.IntValue; decimal decimalValue = cell.DecimalValue; DateTime? dateValue = cell.DateTimeValue; // Check cell data type if (cell.IsNumeric) { Console.WriteLine($"Numeric value: {cell.DecimalValue}"); } else if (cell.IsText) { Console.WriteLine($"Text value: {cell.StringValue}"); } Imports IronXL ' Load workbook and get worksheet Private workBook As WorkBook = WorkBook.Load("test.xlsx") Private workSheet As WorkSheet = workBook.DefaultWorkSheet ' Access cell B1 Private cell As IronXL.Cell = workSheet("B1") ' Read cell value with type safety Private textValue As String = cell.StringValue Private intValue As Integer = cell.IntValue Private decimalValue As Decimal = cell.DecimalValue Private dateValue? As DateTime = cell.DateTimeValue ' Check cell data type If cell.IsNumeric Then Console.WriteLine($"Numeric value: {cell.DecimalValue}") ElseIf cell.IsText Then Console.WriteLine($"Text value: {cell.StringValue}") End If $vbLabelText $csharpLabel The Cell class offers multiple properties for different data types, automatically converting values when possible. For more cell operations, see the Cell formatting tutorial. // Write different data types to cells workSheet["A1"].Value = "Product Name"; // String workSheet["B1"].Value = 99.95m; // Decimal workSheet["C1"].Value = DateTime.Today; // Date workSheet["D1"].Formula = "=B1*1.2"; // Formula // Format cells workSheet["B1"].FormatString = "$#,##0.00"; // Currency format workSheet["C1"].FormatString = "yyyy-MM-dd"; // Date format // Save changes workBook.Save(); // Write different data types to cells workSheet["A1"].Value = "Product Name"; // String workSheet["B1"].Value = 99.95m; // Decimal workSheet["C1"].Value = DateTime.Today; // Date workSheet["D1"].Formula = "=B1*1.2"; // Formula // Format cells workSheet["B1"].FormatString = "$#,##0.00"; // Currency format workSheet["C1"].FormatString = "yyyy-MM-dd"; // Date format // Save changes workBook.Save(); ' Write different data types to cells workSheet("A1").Value = "Product Name" ' String workSheet("B1").Value = 99.95D ' Decimal workSheet("C1").Value = DateTime.Today ' Date workSheet("D1").Formula = "=B1*1.2" ' Formula ' Format cells workSheet("B1").FormatString = "$#,##0.00" ' Currency format workSheet("C1").FormatString = "yyyy-MM-dd" ' Date format ' Save changes workBook.Save() $vbLabelText $csharpLabel How Can I Work with Cell Ranges? The Range class represents a collection of cells, enabling bulk operations on Excel data. // Select range using Excel notation Range range = workSheet["D2:D101"]; // Alternative: Use Range class for dynamic selection Range dynamicRange = workSheet.GetRange(1, 3, 100, 3); // Row 2-101, Column D // Perform bulk operations range.Value = 0; // Set all cells to 0 // Select range using Excel notation Range range = workSheet["D2:D101"]; // Alternative: Use Range class for dynamic selection Range dynamicRange = workSheet.GetRange(1, 3, 100, 3); // Row 2-101, Column D // Perform bulk operations range.Value = 0; // Set all cells to 0 ' Select range using Excel notation Dim range As Range = workSheet("D2:D101") ' Alternative: Use Range class for dynamic selection Dim dynamicRange As Range = workSheet.GetRange(1, 3, 100, 3) ' Row 2-101, Column D ' Perform bulk operations range.Value = 0 ' Set all cells to 0 $vbLabelText $csharpLabel Process ranges efficiently using loops when cell count is known: // Data validation example public class ValidationResult { public int Row { get; set; } public string PhoneError { get; set; } public string EmailError { get; set; } public string DateError { get; set; } public bool IsValid => string.IsNullOrEmpty(PhoneError) && string.IsNullOrEmpty(EmailError) && string.IsNullOrEmpty(DateError); } // Validate data in rows 2-101 var results = new List<ValidationResult>(); for (int row = 2; row <= 101; row++) { var result = new ValidationResult { Row = row }; // Get row data efficiently var phoneCell = workSheet[$"B{row}"]; var emailCell = workSheet[$"D{row}"]; var dateCell = workSheet[$"E{row}"]; // Validate phone number if (!IsValidPhoneNumber(phoneCell.StringValue)) result.PhoneError = "Invalid phone format"; // Validate email if (!IsValidEmail(emailCell.StringValue)) result.EmailError = "Invalid email format"; // Validate date if (!dateCell.IsDateTime) result.DateError = "Invalid date format"; results.Add(result); } // Helper methods bool IsValidPhoneNumber(string phone) => System.Text.RegularExpressions.Regex.IsMatch(phone, @"^\d{3}-\d{3}-\d{4}$"); bool IsValidEmail(string email) => email.Contains("@") && email.Contains("."); // Data validation example public class ValidationResult { public int Row { get; set; } public string PhoneError { get; set; } public string EmailError { get; set; } public string DateError { get; set; } public bool IsValid => string.IsNullOrEmpty(PhoneError) && string.IsNullOrEmpty(EmailError) && string.IsNullOrEmpty(DateError); } // Validate data in rows 2-101 var results = new List<ValidationResult>(); for (int row = 2; row <= 101; row++) { var result = new ValidationResult { Row = row }; // Get row data efficiently var phoneCell = workSheet[$"B{row}"]; var emailCell = workSheet[$"D{row}"]; var dateCell = workSheet[$"E{row}"]; // Validate phone number if (!IsValidPhoneNumber(phoneCell.StringValue)) result.PhoneError = "Invalid phone format"; // Validate email if (!IsValidEmail(emailCell.StringValue)) result.EmailError = "Invalid email format"; // Validate date if (!dateCell.IsDateTime) result.DateError = "Invalid date format"; results.Add(result); } // Helper methods bool IsValidPhoneNumber(string phone) => System.Text.RegularExpressions.Regex.IsMatch(phone, @"^\d{3}-\d{3}-\d{4}$"); bool IsValidEmail(string email) => email.Contains("@") && email.Contains("."); ' Data validation example Public Class ValidationResult Public Property Row() As Integer Public Property PhoneError() As String Public Property EmailError() As String Public Property DateError() As String Public ReadOnly Property IsValid() As Boolean Get Return String.IsNullOrEmpty(PhoneError) AndAlso String.IsNullOrEmpty(EmailError) AndAlso String.IsNullOrEmpty(DateError) End Get End Property End Class ' Validate data in rows 2-101 Private results = New List(Of ValidationResult)() For row As Integer = 2 To 101 Dim result = New ValidationResult With {.Row = row} ' Get row data efficiently Dim phoneCell = workSheet($"B{row}") Dim emailCell = workSheet($"D{row}") Dim dateCell = workSheet($"E{row}") ' Validate phone number If Not IsValidPhoneNumber(phoneCell.StringValue) Then result.PhoneError = "Invalid phone format" End If ' Validate email If Not IsValidEmail(emailCell.StringValue) Then result.EmailError = "Invalid email format" End If ' Validate date If Not dateCell.IsDateTime Then result.DateError = "Invalid date format" End If results.Add(result) Next row ' Helper methods 'INSTANT VB TODO TASK: Local functions are not converted by Instant VB: 'bool IsValidPhoneNumber(string phone) '{ ' Return System.Text.RegularExpressions.Regex.IsMatch(phone, "^\d{3}-\d{3}-\d{4}$"); '} 'INSTANT VB TODO TASK: Local functions are not converted by Instant VB: 'bool IsValidEmail(string email) '{ ' Return email.Contains("@") && email.Contains("."); '} $vbLabelText $csharpLabel How Do I Add Formulas to Excel Spreadsheets? Apply Excel formulas using the Formula property. IronXL supports standard Excel formula syntax. // Add formulas to calculate percentages int lastRow = 50; for (int row = 2; row < lastRow; row++) { // Calculate percentage: current value / total workSheet[$"C{row}"].Formula = $"=B{row}/B{lastRow}"; // Format as percentage workSheet[$"C{row}"].FormatString = "0.00%"; } // Add summary formulas workSheet["B52"].Formula = "=SUM(B2:B50)"; // Sum workSheet["B53"].Formula = "=AVERAGE(B2:B50)"; // Average workSheet["B54"].Formula = "=MAX(B2:B50)"; // Maximum workSheet["B55"].Formula = "=MIN(B2:B50)"; // Minimum // Force formula evaluation workBook.EvaluateAll(); // Add formulas to calculate percentages int lastRow = 50; for (int row = 2; row < lastRow; row++) { // Calculate percentage: current value / total workSheet[$"C{row}"].Formula = $"=B{row}/B{lastRow}"; // Format as percentage workSheet[$"C{row}"].FormatString = "0.00%"; } // Add summary formulas workSheet["B52"].Formula = "=SUM(B2:B50)"; // Sum workSheet["B53"].Formula = "=AVERAGE(B2:B50)"; // Average workSheet["B54"].Formula = "=MAX(B2:B50)"; // Maximum workSheet["B55"].Formula = "=MIN(B2:B50)"; // Minimum // Force formula evaluation workBook.EvaluateAll(); ' Add formulas to calculate percentages Dim lastRow As Integer = 50 Dim row As Integer = 2 Do While row < lastRow ' Calculate percentage: current value / total workSheet($"C{row}").Formula = $"=B{row}/B{lastRow}" ' Format as percentage workSheet($"C{row}").FormatString = "0.00%" row += 1 Loop ' Add summary formulas workSheet("B52").Formula = "=SUM(B2:B50)" ' Sum workSheet("B53").Formula = "=AVERAGE(B2:B50)" ' Average workSheet("B54").Formula = "=MAX(B2:B50)" ' Maximum workSheet("B55").Formula = "=MIN(B2:B50)" ' Minimum ' Force formula evaluation workBook.EvaluateAll() $vbLabelText $csharpLabel To edit existing formulas, explore the Excel formulas tutorial. How Can I Validate Spreadsheet Data? IronXL enables comprehensive data validation for spreadsheets. This example validates phone numbers, emails, and dates using external libraries and built-in C# functionality. using System.Text.RegularExpressions; using IronXL; // Validation implementation for (int i = 2; i <= 101; i++) { var result = new PersonValidationResult { Row = i }; results.Add(result); // Get cells for current person var cells = workSheet[$"A{i}:E{i}"].ToList(); // Validate phone (column B) string phone = cells[1].StringValue; if (!Regex.IsMatch(phone, @"^\+?1?\d{10,14}$")) { result.PhoneNumberErrorMessage = "Invalid phone format"; } // Validate email (column D) string email = cells[3].StringValue; if (!Regex.IsMatch(email, @"^[^@\s]+@[^@\s]+\.[^@\s]+$")) { result.EmailErrorMessage = "Invalid email address"; } // Validate date (column E) if (!cells[4].IsDateTime) { result.DateErrorMessage = "Invalid date format"; } } using System.Text.RegularExpressions; using IronXL; // Validation implementation for (int i = 2; i <= 101; i++) { var result = new PersonValidationResult { Row = i }; results.Add(result); // Get cells for current person var cells = workSheet[$"A{i}:E{i}"].ToList(); // Validate phone (column B) string phone = cells[1].StringValue; if (!Regex.IsMatch(phone, @"^\+?1?\d{10,14}$")) { result.PhoneNumberErrorMessage = "Invalid phone format"; } // Validate email (column D) string email = cells[3].StringValue; if (!Regex.IsMatch(email, @"^[^@\s]+@[^@\s]+\.[^@\s]+$")) { result.EmailErrorMessage = "Invalid email address"; } // Validate date (column E) if (!cells[4].IsDateTime) { result.DateErrorMessage = "Invalid date format"; } } Imports System.Text.RegularExpressions Imports IronXL ' Validation implementation For i As Integer = 2 To 101 Dim result = New PersonValidationResult With {.Row = i} results.Add(result) ' Get cells for current person Dim cells = workSheet($"A{i}:E{i}").ToList() ' Validate phone (column B) Dim phone As String = cells(1).StringValue If Not Regex.IsMatch(phone, "^\+?1?\d{10,14}$") Then result.PhoneNumberErrorMessage = "Invalid phone format" End If ' Validate email (column D) Dim email As String = cells(3).StringValue If Not Regex.IsMatch(email, "^[^@\s]+@[^@\s]+\.[^@\s]+$") Then result.EmailErrorMessage = "Invalid email address" End If ' Validate date (column E) If Not cells(4).IsDateTime Then result.DateErrorMessage = "Invalid date format" End If Next i $vbLabelText $csharpLabel Save validation results to a new worksheet: // Create results worksheet var resultsSheet = workBook.CreateWorkSheet("ValidationResults"); // Add headers resultsSheet["A1"].Value = "Row"; resultsSheet["B1"].Value = "Valid"; resultsSheet["C1"].Value = "Phone Error"; resultsSheet["D1"].Value = "Email Error"; resultsSheet["E1"].Value = "Date Error"; // Style headers resultsSheet["A1:E1"].Style.Font.Bold = true; resultsSheet["A1:E1"].Style.SetBackgroundColor("#4472C4"); resultsSheet["A1:E1"].Style.Font.Color = "#FFFFFF"; // Output validation results for (int i = 0; i < results.Count; i++) { var result = results[i]; int outputRow = i + 2; resultsSheet[$"A{outputRow}"].Value = result.Row; resultsSheet[$"B{outputRow}"].Value = result.IsValid ? "Yes" : "No"; resultsSheet[$"C{outputRow}"].Value = result.PhoneNumberErrorMessage ?? ""; resultsSheet[$"D{outputRow}"].Value = result.EmailErrorMessage ?? ""; resultsSheet[$"E{outputRow}"].Value = result.DateErrorMessage ?? ""; // Highlight invalid rows if (!result.IsValid) { resultsSheet[$"A{outputRow}:E{outputRow}"].Style.SetBackgroundColor("#FFE6E6"); } } // Auto-fit columns for (int col = 0; col < 5; col++) { resultsSheet.AutoSizeColumn(col); } // Save validated workbook workBook.SaveAs(@"Spreadsheets\PeopleValidated.xlsx"); // Create results worksheet var resultsSheet = workBook.CreateWorkSheet("ValidationResults"); // Add headers resultsSheet["A1"].Value = "Row"; resultsSheet["B1"].Value = "Valid"; resultsSheet["C1"].Value = "Phone Error"; resultsSheet["D1"].Value = "Email Error"; resultsSheet["E1"].Value = "Date Error"; // Style headers resultsSheet["A1:E1"].Style.Font.Bold = true; resultsSheet["A1:E1"].Style.SetBackgroundColor("#4472C4"); resultsSheet["A1:E1"].Style.Font.Color = "#FFFFFF"; // Output validation results for (int i = 0; i < results.Count; i++) { var result = results[i]; int outputRow = i + 2; resultsSheet[$"A{outputRow}"].Value = result.Row; resultsSheet[$"B{outputRow}"].Value = result.IsValid ? "Yes" : "No"; resultsSheet[$"C{outputRow}"].Value = result.PhoneNumberErrorMessage ?? ""; resultsSheet[$"D{outputRow}"].Value = result.EmailErrorMessage ?? ""; resultsSheet[$"E{outputRow}"].Value = result.DateErrorMessage ?? ""; // Highlight invalid rows if (!result.IsValid) { resultsSheet[$"A{outputRow}:E{outputRow}"].Style.SetBackgroundColor("#FFE6E6"); } } // Auto-fit columns for (int col = 0; col < 5; col++) { resultsSheet.AutoSizeColumn(col); } // Save validated workbook workBook.SaveAs(@"Spreadsheets\PeopleValidated.xlsx"); ' Create results worksheet Dim resultsSheet = workBook.CreateWorkSheet("ValidationResults") ' Add headers resultsSheet("A1").Value = "Row" resultsSheet("B1").Value = "Valid" resultsSheet("C1").Value = "Phone Error" resultsSheet("D1").Value = "Email Error" resultsSheet("E1").Value = "Date Error" ' Style headers resultsSheet("A1:E1").Style.Font.Bold = True resultsSheet("A1:E1").Style.SetBackgroundColor("#4472C4") resultsSheet("A1:E1").Style.Font.Color = "#FFFFFF" ' Output validation results For i As Integer = 0 To results.Count - 1 Dim result = results(i) Dim outputRow As Integer = i + 2 resultsSheet($"A{outputRow}").Value = result.Row resultsSheet($"B{outputRow}").Value = If(result.IsValid, "Yes", "No") resultsSheet($"C{outputRow}").Value = If(result.PhoneNumberErrorMessage, "") resultsSheet($"D{outputRow}").Value = If(result.EmailErrorMessage, "") resultsSheet($"E{outputRow}").Value = If(result.DateErrorMessage, "") ' Highlight invalid rows If Not result.IsValid Then resultsSheet($"A{outputRow}:E{outputRow}").Style.SetBackgroundColor("#FFE6E6") End If Next i ' Auto-fit columns For col As Integer = 0 To 4 resultsSheet.AutoSizeColumn(col) Next col ' Save validated workbook workBook.SaveAs("Spreadsheets\PeopleValidated.xlsx") $vbLabelText $csharpLabel How Do I Export Excel Data to a Database? Use IronXL with Entity Framework to export spreadsheet data directly to databases. This example demonstrates exporting country GDP data to SQLite. using System; using System.ComponentModel.DataAnnotations; using Microsoft.EntityFrameworkCore; using IronXL; // Define entity model public class Country { [Key] public Guid Id { get; set; } = Guid.NewGuid(); [Required] [MaxLength(100)] public string Name { get; set; } [Range(0, double.MaxValue)] public decimal GDP { get; set; } public DateTime ImportedDate { get; set; } = DateTime.UtcNow; } using System; using System.ComponentModel.DataAnnotations; using Microsoft.EntityFrameworkCore; using IronXL; // Define entity model public class Country { [Key] public Guid Id { get; set; } = Guid.NewGuid(); [Required] [MaxLength(100)] public string Name { get; set; } [Range(0, double.MaxValue)] public decimal GDP { get; set; } public DateTime ImportedDate { get; set; } = DateTime.UtcNow; } Imports System Imports System.ComponentModel.DataAnnotations Imports Microsoft.EntityFrameworkCore Imports IronXL ' Define entity model Public Class Country <Key> Public Property Id() As Guid = Guid.NewGuid() <Required> <MaxLength(100)> Public Property Name() As String <Range(0, Double.MaxValue)> Public Property GDP() As Decimal Public Property ImportedDate() As DateTime = DateTime.UtcNow End Class $vbLabelText $csharpLabel Configure Entity Framework context for database operations: public class CountryContext : DbContext { public DbSet<Country> Countries { get; set; } protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) { // Configure SQLite connection optionsBuilder.UseSqlite("Data Source=CountryGDP.db"); // Enable sensitive data logging in development #if DEBUG optionsBuilder.EnableSensitiveDataLogging(); #endif } protected override void OnModelCreating(ModelBuilder modelBuilder) { // Configure decimal precision modelBuilder.Entity<Country>() .Property(c => c.GDP) .HasPrecision(18, 2); } } public class CountryContext : DbContext { public DbSet<Country> Countries { get; set; } protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) { // Configure SQLite connection optionsBuilder.UseSqlite("Data Source=CountryGDP.db"); // Enable sensitive data logging in development #if DEBUG optionsBuilder.EnableSensitiveDataLogging(); #endif } protected override void OnModelCreating(ModelBuilder modelBuilder) { // Configure decimal precision modelBuilder.Entity<Country>() .Property(c => c.GDP) .HasPrecision(18, 2); } } Public Class CountryContext Inherits DbContext Public Property Countries() As DbSet(Of Country) Protected Overrides Sub OnConfiguring(ByVal optionsBuilder As DbContextOptionsBuilder) ' Configure SQLite connection optionsBuilder.UseSqlite("Data Source=CountryGDP.db") ' Enable sensitive data logging in development #If DEBUG Then optionsBuilder.EnableSensitiveDataLogging() #End If End Sub Protected Overrides Sub OnModelCreating(ByVal modelBuilder As ModelBuilder) ' Configure decimal precision modelBuilder.Entity(Of Country)().Property(Function(c) c.GDP).HasPrecision(18, 2) End Sub End Class $vbLabelText $csharpLabel Please noteNote: To use different databases, install the appropriate NuGet package (e.g., Microsoft.EntityFrameworkCore.SqlServer for SQL Server) and modify the connection configuration accordingly. Import Excel data to database: using System.Threading.Tasks; using IronXL; using Microsoft.EntityFrameworkCore; public async Task ImportGDPDataAsync() { try { // Load Excel file var workBook = WorkBook.Load(@"Spreadsheets\GDP.xlsx"); var workSheet = workBook.GetWorkSheet("GDPByCountry"); using (var context = new CountryContext()) { // Ensure database exists await context.Database.EnsureCreatedAsync(); // Clear existing data (optional) await context.Database.ExecuteSqlRawAsync("DELETE FROM Countries"); // Import data with progress tracking int totalRows = 213; for (int row = 2; row <= totalRows; row++) { // Read country data var countryName = workSheet[$"A{row}"].StringValue; var gdpValue = workSheet[$"B{row}"].DecimalValue; // Skip empty rows if (string.IsNullOrWhiteSpace(countryName)) continue; // Create and add entity var country = new Country { Name = countryName.Trim(), GDP = gdpValue * 1_000_000 // Convert to actual value if in millions }; await context.Countries.AddAsync(country); // Save in batches for performance if (row % 50 == 0) { await context.SaveChangesAsync(); Console.WriteLine($"Imported {row - 1} of {totalRows} countries"); } } // Save remaining records await context.SaveChangesAsync(); Console.WriteLine($"Successfully imported {await context.Countries.CountAsync()} countries"); } } catch (Exception ex) { Console.WriteLine($"Import failed: {ex.Message}"); throw; } } using System.Threading.Tasks; using IronXL; using Microsoft.EntityFrameworkCore; public async Task ImportGDPDataAsync() { try { // Load Excel file var workBook = WorkBook.Load(@"Spreadsheets\GDP.xlsx"); var workSheet = workBook.GetWorkSheet("GDPByCountry"); using (var context = new CountryContext()) { // Ensure database exists await context.Database.EnsureCreatedAsync(); // Clear existing data (optional) await context.Database.ExecuteSqlRawAsync("DELETE FROM Countries"); // Import data with progress tracking int totalRows = 213; for (int row = 2; row <= totalRows; row++) { // Read country data var countryName = workSheet[$"A{row}"].StringValue; var gdpValue = workSheet[$"B{row}"].DecimalValue; // Skip empty rows if (string.IsNullOrWhiteSpace(countryName)) continue; // Create and add entity var country = new Country { Name = countryName.Trim(), GDP = gdpValue * 1_000_000 // Convert to actual value if in millions }; await context.Countries.AddAsync(country); // Save in batches for performance if (row % 50 == 0) { await context.SaveChangesAsync(); Console.WriteLine($"Imported {row - 1} of {totalRows} countries"); } } // Save remaining records await context.SaveChangesAsync(); Console.WriteLine($"Successfully imported {await context.Countries.CountAsync()} countries"); } } catch (Exception ex) { Console.WriteLine($"Import failed: {ex.Message}"); throw; } } Imports System.Threading.Tasks Imports IronXL Imports Microsoft.EntityFrameworkCore Public Async Function ImportGDPDataAsync() As Task Try ' Load Excel file Dim workBook = WorkBook.Load("Spreadsheets\GDP.xlsx") Dim workSheet = workBook.GetWorkSheet("GDPByCountry") Using context = New CountryContext() ' Ensure database exists Await context.Database.EnsureCreatedAsync() ' Clear existing data (optional) Await context.Database.ExecuteSqlRawAsync("DELETE FROM Countries") ' Import data with progress tracking Dim totalRows As Integer = 213 Dim row As Integer = 2 Do While row <= totalRows ' Read country data Dim countryName = workSheet($"A{row}").StringValue Dim gdpValue = workSheet($"B{row}").DecimalValue ' Skip empty rows If String.IsNullOrWhiteSpace(countryName) Then row += 1 Continue Do End If ' Create and add entity Dim country As New Country With { .Name = countryName.Trim(), .GDP = gdpValue * 1_000_000 } Await context.Countries.AddAsync(country) ' Save in batches for performance If row Mod 50 = 0 Then Await context.SaveChangesAsync() Console.WriteLine($"Imported {row - 1} of {totalRows} countries") End If row += 1 Loop ' Save remaining records Await context.SaveChangesAsync() Console.WriteLine($"Successfully imported {Await context.Countries.CountAsync()} countries") End Using Catch ex As Exception Console.WriteLine($"Import failed: {ex.Message}") Throw End Try End Function $vbLabelText $csharpLabel How Can I Import API Data into Excel Spreadsheets? Combine IronXL with HTTP clients to populate spreadsheets with live API data. This example uses RestClient.Net to fetch country data. using System; using System.Collections.Generic; using System.Net.Http; using System.Threading.Tasks; using Newtonsoft.Json; using IronXL; // Define data model matching API response public class RestCountry { public string Name { get; set; } public long Population { get; set; } public string Region { get; set; } public string NumericCode { get; set; } public List<Language> Languages { get; set; } } public class Language { public string Name { get; set; } public string NativeName { get; set; } } // Fetch and process API data public async Task ImportCountryDataAsync() { using var httpClient = new HttpClient(); try { // Call REST API var response = await httpClient.GetStringAsync("https://restcountries.com/v3.1/all"); var countries = JsonConvert.DeserializeObject<List<RestCountry>>(response); // Create new workbook var workBook = WorkBook.Create(ExcelFileFormat.XLSX); var workSheet = workBook.CreateWorkSheet("Countries"); // Add headers with styling string[] headers = { "Country", "Population", "Region", "Code", "Language 1", "Language 2", "Language 3" }; for (int col = 0; col < headers.Length; col++) { var headerCell = workSheet[0, col]; headerCell.Value = headers[col]; headerCell.Style.Font.Bold = true; headerCell.Style.SetBackgroundColor("#366092"); headerCell.Style.Font.Color = "#FFFFFF"; } // Import country data await ProcessCountryData(countries, workSheet); // Save workbook workBook.SaveAs("CountriesFromAPI.xlsx"); } catch (Exception ex) { Console.WriteLine($"API import failed: {ex.Message}"); } } using System; using System.Collections.Generic; using System.Net.Http; using System.Threading.Tasks; using Newtonsoft.Json; using IronXL; // Define data model matching API response public class RestCountry { public string Name { get; set; } public long Population { get; set; } public string Region { get; set; } public string NumericCode { get; set; } public List<Language> Languages { get; set; } } public class Language { public string Name { get; set; } public string NativeName { get; set; } } // Fetch and process API data public async Task ImportCountryDataAsync() { using var httpClient = new HttpClient(); try { // Call REST API var response = await httpClient.GetStringAsync("https://restcountries.com/v3.1/all"); var countries = JsonConvert.DeserializeObject<List<RestCountry>>(response); // Create new workbook var workBook = WorkBook.Create(ExcelFileFormat.XLSX); var workSheet = workBook.CreateWorkSheet("Countries"); // Add headers with styling string[] headers = { "Country", "Population", "Region", "Code", "Language 1", "Language 2", "Language 3" }; for (int col = 0; col < headers.Length; col++) { var headerCell = workSheet[0, col]; headerCell.Value = headers[col]; headerCell.Style.Font.Bold = true; headerCell.Style.SetBackgroundColor("#366092"); headerCell.Style.Font.Color = "#FFFFFF"; } // Import country data await ProcessCountryData(countries, workSheet); // Save workbook workBook.SaveAs("CountriesFromAPI.xlsx"); } catch (Exception ex) { Console.WriteLine($"API import failed: {ex.Message}"); } } Imports System Imports System.Collections.Generic Imports System.Net.Http Imports System.Threading.Tasks Imports Newtonsoft.Json Imports IronXL ' Define data model matching API response Public Class RestCountry Public Property Name() As String Public Property Population() As Long Public Property Region() As String Public Property NumericCode() As String Public Property Languages() As List(Of Language) End Class Public Class Language Public Property Name() As String Public Property NativeName() As String End Class ' Fetch and process API data Public Async Function ImportCountryDataAsync() As Task Dim httpClient As New HttpClient() Try ' Call REST API Dim response = Await httpClient.GetStringAsync("https://restcountries.com/v3.1/all") Dim countries = JsonConvert.DeserializeObject(Of List(Of RestCountry))(response) ' Create new workbook Dim workBook = WorkBook.Create(ExcelFileFormat.XLSX) Dim workSheet = workBook.CreateWorkSheet("Countries") ' Add headers with styling Dim headers() As String = { "Country", "Population", "Region", "Code", "Language 1", "Language 2", "Language 3" } For col As Integer = 0 To headers.Length - 1 Dim headerCell = workSheet(0, col) headerCell.Value = headers(col) headerCell.Style.Font.Bold = True headerCell.Style.SetBackgroundColor("#366092") headerCell.Style.Font.Color = "#FFFFFF" Next col ' Import country data Await ProcessCountryData(countries, workSheet) ' Save workbook workBook.SaveAs("CountriesFromAPI.xlsx") Catch ex As Exception Console.WriteLine($"API import failed: {ex.Message}") End Try End Function $vbLabelText $csharpLabel The API returns JSON data in this format: Sample JSON response from the REST Countries API showing hierarchical country information. Process and write the API data to Excel: private async Task ProcessCountryData(List<RestCountry> countries, WorkSheet workSheet) { for (int i = 0; i < countries.Count; i++) { var country = countries[i]; int row = i + 1; // Start from row 1 (after headers) // Write basic country data workSheet[$"A{row}"].Value = country.Name; workSheet[$"B{row}"].Value = country.Population; workSheet[$"C{row}"].Value = country.Region; workSheet[$"D{row}"].Value = country.NumericCode; // Format population with thousands separator workSheet[$"B{row}"].FormatString = "#,##0"; // Add up to 3 languages for (int langIndex = 0; langIndex < Math.Min(3, country.Languages?.Count ?? 0); langIndex++) { var language = country.Languages[langIndex]; string columnLetter = ((char)('E' + langIndex)).ToString(); workSheet[$"{columnLetter}{row}"].Value = language.Name; } // Add conditional formatting for regions if (country.Region == "Europe") { workSheet[$"C{row}"].Style.SetBackgroundColor("#E6F3FF"); } else if (country.Region == "Asia") { workSheet[$"C{row}"].Style.SetBackgroundColor("#FFF2E6"); } // Show progress every 50 countries if (i % 50 == 0) { Console.WriteLine($"Processed {i} of {countries.Count} countries"); } } // Auto-size all columns for (int col = 0; col < 7; col++) { workSheet.AutoSizeColumn(col); } } private async Task ProcessCountryData(List<RestCountry> countries, WorkSheet workSheet) { for (int i = 0; i < countries.Count; i++) { var country = countries[i]; int row = i + 1; // Start from row 1 (after headers) // Write basic country data workSheet[$"A{row}"].Value = country.Name; workSheet[$"B{row}"].Value = country.Population; workSheet[$"C{row}"].Value = country.Region; workSheet[$"D{row}"].Value = country.NumericCode; // Format population with thousands separator workSheet[$"B{row}"].FormatString = "#,##0"; // Add up to 3 languages for (int langIndex = 0; langIndex < Math.Min(3, country.Languages?.Count ?? 0); langIndex++) { var language = country.Languages[langIndex]; string columnLetter = ((char)('E' + langIndex)).ToString(); workSheet[$"{columnLetter}{row}"].Value = language.Name; } // Add conditional formatting for regions if (country.Region == "Europe") { workSheet[$"C{row}"].Style.SetBackgroundColor("#E6F3FF"); } else if (country.Region == "Asia") { workSheet[$"C{row}"].Style.SetBackgroundColor("#FFF2E6"); } // Show progress every 50 countries if (i % 50 == 0) { Console.WriteLine($"Processed {i} of {countries.Count} countries"); } } // Auto-size all columns for (int col = 0; col < 7; col++) { workSheet.AutoSizeColumn(col); } } Private Async Function ProcessCountryData(ByVal countries As List(Of RestCountry), ByVal workSheet As WorkSheet) As Task For i As Integer = 0 To countries.Count - 1 Dim country = countries(i) Dim row As Integer = i + 1 ' Start from row 1 (after headers) ' Write basic country data workSheet($"A{row}").Value = country.Name workSheet($"B{row}").Value = country.Population workSheet($"C{row}").Value = country.Region workSheet($"D{row}").Value = country.NumericCode ' Format population with thousands separator workSheet($"B{row}").FormatString = "#,##0" ' Add up to 3 languages For langIndex As Integer = 0 To Math.Min(3, If(country.Languages?.Count, 0)) - 1 Dim language = country.Languages(langIndex) Dim columnLetter As String = (ChrW(AscW("E"c) + langIndex)).ToString() workSheet($"{columnLetter}{row}").Value = language.Name Next langIndex ' Add conditional formatting for regions If country.Region = "Europe" Then workSheet($"C{row}").Style.SetBackgroundColor("#E6F3FF") ElseIf country.Region = "Asia" Then workSheet($"C{row}").Style.SetBackgroundColor("#FFF2E6") End If ' Show progress every 50 countries If i Mod 50 = 0 Then Console.WriteLine($"Processed {i} of {countries.Count} countries") End If Next i ' Auto-size all columns For col As Integer = 0 To 6 workSheet.AutoSizeColumn(col) Next col End Function $vbLabelText $csharpLabel Object Reference and Resources Explore the comprehensive IronXL API Reference for detailed class documentation and advanced features. Additional tutorials for Excel operations: Create Excel files programmatically Excel formatting and styling guide Working with Excel formulas Excel chart creation tutorial Summary IronXL.Excel is a comprehensive .NET library for reading and manipulating Excel files in various formats. It operates independently without requiring Microsoft Excel or Interop installation. For cloud-based spreadsheet manipulation, you might also explore the Google Sheets API Client Library for .NET, which complements IronXL's local file capabilities. Ready to implement Excel automation in your C# projects? Download IronXL or explore licensing options for production use. Frequently Asked Questions What is the best C# library for reading Excel files without Microsoft Office? IronXL is the leading .NET Excel library for reading and manipulating Excel files without requiring Microsoft Office or Interop. It provides a simple API with methods like WorkBook.Load() for reading files and intuitive cell access using syntax like sheet["A1"].Value. How do I install a C# Excel library using NuGet? Install IronXL via NuGet Package Manager in Visual Studio by searching for 'IronXL.Excel' and clicking Install. Alternatively, use the Package Manager Console with the command Install-Package IronXL.Excel to add Excel functionality to your project. Can I read both XLS and XLSX files in C# without Interop? Yes, IronXL supports reading both legacy XLS and modern XLSX formats using the same WorkBook.Load() method. The library automatically detects the file format and handles the conversion internally. How do I access specific cells and ranges in Excel using C#? IronXL provides intuitive syntax for cell access: use sheet["A1"] for individual cells or sheet["A1:B10"] for ranges. Access cell values with properties like StringValue, IntValue, or DecimalValue for type-safe operations. How can I validate Excel data programmatically in C#? Use IronXL to iterate through cells and apply validation logic. Access cells with sheet["A1:E100"], then validate using C# methods like regex for emails or custom functions for business rules. Create validation reports in new worksheets using CreateWorkSheet(). Can I add formulas to Excel spreadsheets programmatically? Yes, IronXL supports Excel formulas through the Formula property. Set formulas like cell.Formula = "=SUM(A1:A10)" and use workBook.EvaluateAll() to calculate results programmatically. How do I export Excel data to a SQL database using C#? Read Excel data using IronXL's WorkBook.Load() and GetWorkSheet() methods, then iterate through cells to create entity objects. Use Entity Framework's AddAsync() and SaveChangesAsync() to persist data to your database. Can I import REST API data directly into Excel files? Yes, combine IronXL with HTTP clients to fetch API data and populate spreadsheets. Use WorkBook.Create() to create new files, then write API responses to cells using sheet["A1"].Value. IronXL handles all Excel formatting and structure. How do I integrate Excel functionality with ASP.NET Core applications? IronXL fully supports ASP.NET Core. Install via NuGet, then use WorkBook and WorkSheet classes in your controllers. Generate Excel reports, process uploads, or create downloads using IronXL's memory-efficient streaming capabilities. What are the licensing options for Excel libraries in production? IronXL offers a free trial for development and testing. Production licenses start from $749, include dedicated support from .NET engineers, and cover deployment across servers, desktop, and cloud environments without additional Office licensing requirements. Jacob Mellor Chat with engineering team now Chief Technology Officer Jacob Mellor is Chief Technology Officer at Iron Software and a visionary engineer pioneering C# PDF technology. As the original developer behind Iron Software's core codebase, he has shaped the company's product architecture since its inception, transforming it alongside CEO Cameron Rimington into a 50+ person company serving NASA, Tesla, and global government agencies.Jacob holds a First-Class Honours Bachelor of Engineering (BEng) in Civil Engineering from the University of Manchester (1998–2001). After opening his first software business in London in 1999 and creating his first .NET components in 2005, he specialized in solving complex problems across the Microsoft ecosystem.His flagship IronPDF & IronSuite .NET libraries have achieved over 30 million NuGet installations globally, with his foundational code continuing to power developer tools used worldwide. With 25 years of commercial experience and 41 years of coding expertise, Jacob remains focused on driving innovation in enterprise-grade C#, Java, and Python PDF technologies while mentoring the next generation of technical leaders. 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