C# Read Excel Files with Examples

by Christian Findlay

This tutorial explains how to read data from Excel in C# and use the library for everyday tasks like validation, conversion to a database, saving data from Web APIs, and modifying formulae within the spreadsheet. This article references the IronXL code samples, which is a .NET Core Console App.

Code Examples

Read XLS or XLSX File 
using IronXL;
using System.Linq;
    
//Supported spreadsheet formats for reading include: XLSX, XLS, CSV and TSV
WorkBook workbook = WorkBook.Load("test.xlsx");
WorkSheet sheet = workbook.WorkSheets.First();
//Select cells easily in Excel notation and return the calculated value
int cellValue = sheet["A2"].IntValue;
// Read from Ranges of cells elegantly.
foreach (var cell in sheet["A2:A10"])
{
    Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text);
}


///Advanced Operations

//Calculate aggregate values such as Min, Max and Sum
decimal sum = sheet["A2:A10"].Sum();
//Linq compatible
decimal max = sheet["A2:A10"].Max(c => c.DecimalValue);
Imports IronXL
Imports System.Linq

'Supported spreadsheet formats for reading include: XLSX, XLS, CSV and TSV
Private workbook As WorkBook = WorkBook.Load("test.xlsx")
Private sheet As WorkSheet = workbook.WorkSheets.First()
'Select cells easily in Excel notation and return the calculated value
Private cellValue As Integer = sheet("A2").IntValue
' Read from Ranges of cells elegantly.
For Each cell In sheet("A2:A10")
	Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text)
Next cell


'''Advanced Operations

'Calculate aggregate values such as Min, Max and Sum
Dim sum As Decimal = sheet("A2:A10").Sum()
'Linq compatible
Dim max As Decimal = sheet("A2:A10").Max(Function(c) c.DecimalValue)
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Load WorkBook 
var workbook = WorkBook.Load(@"Spreadsheets\\GDP.xlsx");
Dim workbook = WorkBook.Load("Spreadsheets\\GDP.xlsx")
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Create WorkBook 
var workbook = new WorkBook(ExcelFileFormat.XLSX);
Dim workbook = New WorkBook(ExcelFileFormat.XLSX)
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Edit Cell Values in Range 
//Iterate through the rows
for (var y = 2; y <= 101; y++)
{
    var result = new PersonValidationResult { Row = y };
    results.Add(result);

    //Get all cells for the person
    var cells = worksheet[$"A{y}:E{y}"].ToList();

    //Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    //Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    //Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}
'Iterate through the rows
For y = 2 To 101
	Dim result = New PersonValidationResult With {.Row = y}
	results.Add(result)

	'Get all cells for the person
	Dim cells = worksheet($"A{y}:E{y}").ToList()

	'Validate the phone number (1 = B)
	Dim phoneNumber = cells(1).Value
	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, CStr(phoneNumber))

	'Validate the email address (3 = D)
	result.EmailErrorMessage = ValidateEmailAddress(CStr(cells(3).Value))

	'Get the raw date in the format of Month Day[suffix], Year (4 = E)
	Dim rawDate = CStr(cells(4).Value)
	result.DateErrorMessage = ValidateDate(rawDate)
Next y
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Validate Spreadsheet Data 
//Iterate through the rows
for (var i = 2; i <= 101; i++)
{
    var result = new PersonValidationResult { Row = i };
    results.Add(result);

    //Get all cells for the person
    var cells = worksheet[$"A{i}:E{i}"].ToList();

    //Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    //Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    //Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}
'Iterate through the rows
For i = 2 To 101
	Dim result = New PersonValidationResult With {.Row = i}
	results.Add(result)

	'Get all cells for the person
	Dim cells = worksheet($"A{i}:E{i}").ToList()

	'Validate the phone number (1 = B)
	Dim phoneNumber = cells(1).Value
	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, CStr(phoneNumber))

	'Validate the email address (3 = D)
	result.EmailErrorMessage = ValidateEmailAddress(CStr(cells(3).Value))

	'Get the raw date in the format of Month Day[suffix], Year (4 = E)
	Dim rawDate = CStr(cells(4).Value)
	result.DateErrorMessage = ValidateDate(rawDate)
Next i
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Export Data using Entity Framework 
public class CountryContext : DbContext
{
    public DbSet<Country> Countries { get; set; }

    public CountryContext()
    {
        //TODO: Make async
        Database.EnsureCreated();
    }

    /// <summary>
    /// Configure context to use Sqlite
    /// </summary>
    /// <param name="optionsBuilder"></param>
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        var connection = new SqliteConnection($"Data Source=Country.db");
        connection.Open();

        var command = connection.CreateCommand();

        //Create the database if it doesn't already exist
        command.CommandText = $"PRAGMA foreign_keys = ON;";
        command.ExecuteNonQuery();

        optionsBuilder.UseSqlite(connection);

        base.OnConfiguring(optionsBuilder);
    }

}
Public Class CountryContext
	Inherits DbContext

	Public Property Countries() As DbSet(Of Country)

	Public Sub New()
		'TODO: Make async
		Database.EnsureCreated()
	End Sub

	''' <summary>
	''' Configure context to use Sqlite
	''' </summary>
	''' <param name="optionsBuilder"></param>
	Protected Overrides Sub OnConfiguring(ByVal optionsBuilder As DbContextOptionsBuilder)
		Dim connection = New SqliteConnection($"Data Source=Country.db")
		connection.Open()

		Dim command = connection.CreateCommand()

		'Create the database if it doesn't already exist
		command.CommandText = $"PRAGMA foreign_keys = ON;"
		command.ExecuteNonQuery()

		optionsBuilder.UseSqlite(connection)

		MyBase.OnConfiguring(optionsBuilder)
	End Sub

End Class
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Add Spreadsheet Formulae 
//Iterate through all rows with a value
for (var y = 2; y < i; y++)
{
    //Get the C cell
    var cell = sheet[$"C{y}"].First();

    //Set the formula for the Percentage of Total column
    cell.Formula = $"=B{y}/B{i}";
}
'Iterate through all rows with a value
Dim y = 2
Do While y < i
	'Get the C cell
	Dim cell = sheet($"C{y}").First()

	'Set the formula for the Percentage of Total column
	cell.Formula = $"=B{y}/B{i}"
	y += 1
Loop
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Data API to Spreadsheet 
var client = new Client(new Uri("https://restcountries.eu/rest/v2/"));
List<RestCountry> countries = await client.GetAsync<List<RestCountry>>();
Dim client = New Client(New Uri("https://restcountries.eu/rest/v2/"))
Dim countries As List(Of RestCountry) = Await client.GetAsync(Of List(Of RestCountry))()
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Try IronXL free for development

How To Read Excel Files in C# .NET:

Overview

Read Data from Excel in .NET using IronXL

IronXL is a .NET library that facilitates reading and editing Microsoft Excel documents with C#. This tutorial will walk you through using C sharp code to read Excel files.

  1. Install the IronXL Excel Library. We can do this using our NuGet package or by downloading the .Net Excel DLL.
  2. Use the WorkBook.Load method to read any XLS, XLSX or CSV document.
  3. Get Cell values using intuitive syntax: sheet["A11"].DecimalValue

IronXL Includes:

  • Dedicated product support from our .NET engineers
  • Easy installation via Microsoft Visual Studio
  • FREE for development. Licenses from $399.

We will see how easy it is to read Excel files in C# or VB.Net using the IronXL library. The samples contain three Excel spreadsheets.

Read XLS or XLSX Files: Quick Code

In this example we can see that Excel files can be read efficiently without Interop in C#. The final Advanced Operations show Linq compatibility and aggregate range mathematics.

using IronXL;
using System.Linq;

//Supported spreadsheet formats for reading include: XLSX, XLS, CSV and TSV
WorkBook workbook = WorkBook.Load("test.xlsx");
WorkSheet sheet = workbook.WorkSheets.First();
//Select cells easily in Excel notation and return the calculated value
int cellValue = sheet["A2"].IntValue;
// Read from Ranges of cells elegantly.
foreach (var cell in sheet["A2:A10"])
{
    Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text);
}

///Advanced Operations

//Calculate aggregate values such as Min, Max and Sum
decimal sum = sheet["A2:A10"].Sum();
//Linq compatible
decimal max = sheet["A2:A10"].Max(c => c.DecimalValue);
using IronXL;
using System.Linq;

//Supported spreadsheet formats for reading include: XLSX, XLS, CSV and TSV
WorkBook workbook = WorkBook.Load("test.xlsx");
WorkSheet sheet = workbook.WorkSheets.First();
//Select cells easily in Excel notation and return the calculated value
int cellValue = sheet["A2"].IntValue;
// Read from Ranges of cells elegantly.
foreach (var cell in sheet["A2:A10"])
{
    Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text);
}

///Advanced Operations

//Calculate aggregate values such as Min, Max and Sum
decimal sum = sheet["A2:A10"].Sum();
//Linq compatible
decimal max = sheet["A2:A10"].Max(c => c.DecimalValue);
Imports IronXL
Imports System.Linq

'Supported spreadsheet formats for reading include: XLSX, XLS, CSV and TSV
Private workbook As WorkBook = WorkBook.Load("test.xlsx")
Private sheet As WorkSheet = workbook.WorkSheets.First()
'Select cells easily in Excel notation and return the calculated value
Private cellValue As Integer = sheet("A2").IntValue
' Read from Ranges of cells elegantly.
For Each cell In sheet("A2:A10")
	Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text)
Next cell

'''Advanced Operations

'Calculate aggregate values such as Min, Max and Sum
Dim sum As Decimal = sheet("A2:A10").Sum()
'Linq compatible
Dim max As Decimal = sheet("A2:A10").Max(Function(c) c.DecimalValue)
VB   C#

Step 1

1. Download the IronXL C# Library for FREE

C# PDF DLL

Download DLL

Download DLL

Manually install into your project

or
C# Nuget Library for PDF

Install with NuGet

Install-Package IronXL.Excel
nuget.org/packages/IronXL.Excel/

The first thing we need to do is install the IronXL.Excel library, adding Excel functionality to the .NET framework.

Installing the IronXL Nuget Package

  1. In Visual Studio, right-click on the project select "Manage Nuget Packages ..."
  2. Search for the IronXL.Excel package and install


Another way to install is:

  1. Enter the Package Manager Console
  2. Type > Install-Package IronXL.Excel
 PM > Install-Package IronXL.Excel


Additionally, you can view the package on the NuGet site here.

Direct Download Installation

Alternatively, we can start by downloading the IronXL .NET Excel DLL and manually installing into Visual Studio.

How To Tutorials

2. Load a WorkBook

The WorkBook class represents an Excel spreadsheet. To open a WorkBook, use WorkBook.Load and specify the path of the Excel file (.xlsx)

var workbook = WorkBook.Load(@"Spreadsheets\\GDP.xlsx");
var workbook = WorkBook.Load(@"Spreadsheets\\GDP.xlsx");
Dim workbook = WorkBook.Load("Spreadsheets\\GDP.xlsx")
VB   C#

Sample: ExcelToDBProcessor

Each WorkBook can have multiple WorkSheet objects. These represent worksheets in the Excel document. If the spreadsheet contains worksheets, retrieve them by name WorkBook.GetWorkSheet.

var worksheet = workbook.GetWorkSheet("GDPByCountry");
var worksheet = workbook.GetWorkSheet("GDPByCountry");
Dim worksheet = workbook.GetWorkSheet("GDPByCountry")
VB   C#

Sample: ExcelToDB

3. Create a WorkBook

To create a new WorkBook in memory, construct a new WorkBook with the spreadsheet type.

var workbook = new WorkBook(ExcelFileFormat.XLSX);
var workbook = new WorkBook(ExcelFileFormat.XLSX);
Dim workbook = New WorkBook(ExcelFileFormat.XLSX)
VB   C#

Sample: ApiToExcelProcessor

Note: Use ExcelFileFormat.XLS for legacy for Excel spreadsheets (95 and earlier)

4. Create a WorkSheet

Each "WorkBook" can have multiple WorkSheets. A "WorkSheet" is a sheet of data, while a WorkBook represents a collection of WorkSheets. This is how one workbook with two worksheets looks in Excel:

To create a new WorkSheet call WorkBook.CreateWorkSheet and pass the name of the worksheet

var worksheet = workbook.CreateWorkSheet("Countries");
var worksheet = workbook.CreateWorkSheet("Countries");
Dim worksheet = workbook.CreateWorkSheet("Countries")
VB   C#

5. Get Cell Range

The "Range" class represents a two-dimensional collection of "Cell" objects. It represents a literal range of Excel cells. Obtain ranges by using the string indexer on a WorkSheet object. The argument text is either the coordinate of a cell (e.g. "A1") or a span of cells from left to right top to bottom (e.g. "B2:E5"). It is also possible to call GetRange on a WorkSheet.

var range = worksheet["D2:D101"];
var range = worksheet["D2:D101"];
Dim range = worksheet("D2:D101")
VB   C#

Sample: DataValidation

6. Edit Cell Values Within a Range

There are several ways to read or edit the values of cells within a Range. If the count is known, use a For loop.

//Iterate through the rows
for (var y = 2; y <= 101; y++)
{
    var result = new PersonValidationResult { Row = y };
    results.Add(result);

    //Get all cells for the person
    var cells = worksheet[$"A{y}:E{y}"].ToList();

    //Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    //Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    //Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}
//Iterate through the rows
for (var y = 2; y <= 101; y++)
{
    var result = new PersonValidationResult { Row = y };
    results.Add(result);

    //Get all cells for the person
    var cells = worksheet[$"A{y}:E{y}"].ToList();

    //Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    //Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    //Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}
'Iterate through the rows
For y = 2 To 101
	Dim result = New PersonValidationResult With {.Row = y}
	results.Add(result)

	'Get all cells for the person
	Dim cells = worksheet($"A{y}:E{y}").ToList()

	'Validate the phone number (1 = B)
	Dim phoneNumber = cells(1).Value
	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, CStr(phoneNumber))

	'Validate the email address (3 = D)
	result.EmailErrorMessage = ValidateEmailAddress(CStr(cells(3).Value))

	'Get the raw date in the format of Month Day[suffix], Year (4 = E)
	Dim rawDate = CStr(cells(4).Value)
	result.DateErrorMessage = ValidateDate(rawDate)
Next y
VB   C#

Sample: DataValidation

7. Validate Spreadsheet Data

Use IronXL to validate a spreadsheet of data. The DataValidation sample uses libphonenumber-csharp to validate phone numbers and uses standard C# APIs to validate email addresses and dates.

//Iterate through the rows
for (var i = 2; i <= 101; i++)
{
    var result = new PersonValidationResult { Row = i };
    results.Add(result);

    //Get all cells for the person
    var cells = worksheet[$"A{i}:E{i}"].ToList();

    //Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    //Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    //Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}
//Iterate through the rows
for (var i = 2; i <= 101; i++)
{
    var result = new PersonValidationResult { Row = i };
    results.Add(result);

    //Get all cells for the person
    var cells = worksheet[$"A{i}:E{i}"].ToList();

    //Validate the phone number (1 = B)
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    //Validate the email address (3 = D)
    result.EmailErrorMessage = ValidateEmailAddress((string)cells[3].Value);

    //Get the raw date in the format of Month Day[suffix], Year (4 = E)
    var rawDate = (string)cells[4].Value;
    result.DateErrorMessage = ValidateDate(rawDate);
}
'Iterate through the rows
For i = 2 To 101
	Dim result = New PersonValidationResult With {.Row = i}
	results.Add(result)

	'Get all cells for the person
	Dim cells = worksheet($"A{i}:E{i}").ToList()

	'Validate the phone number (1 = B)
	Dim phoneNumber = cells(1).Value
	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, CStr(phoneNumber))

	'Validate the email address (3 = D)
	result.EmailErrorMessage = ValidateEmailAddress(CStr(cells(3).Value))

	'Get the raw date in the format of Month Day[suffix], Year (4 = E)
	Dim rawDate = CStr(cells(4).Value)
	result.DateErrorMessage = ValidateDate(rawDate)
Next i
VB   C#

The above code loops through each row in the spreadsheet and grabs the cells as a list. Each validates method checks the value of a cell and returns an error message if the value is invalid.

This code creates a new spreadsheet, specifies headers, and outputs the error message results so that there is a log of invalid data.

var resultsSheet = workbook.CreateWorkSheet("Results");

resultsSheet["A1"].Value = "Row";
resultsSheet["B1"].Value = "Valid";
resultsSheet["C1"].Value = "Phone Error";
resultsSheet["D1"].Value = "Email Error";
resultsSheet["E1"].Value = "Date Error";

for (var i = 0; i < results.Count; i++)
{
    var result = results[i];
    resultsSheet[$"A{i + 2}"].Value = result.Row;
    resultsSheet[$"B{i + 2}"].Value = result.IsValid ? "Yes" : "No";
    resultsSheet[$"C{i + 2}"].Value = result.PhoneNumberErrorMessage;
    resultsSheet[$"D{i + 2}"].Value = result.EmailErrorMessage;
    resultsSheet[$"E{i + 2}"].Value = result.DateErrorMessage;
}

workbook.SaveAs(@"Spreadsheets\\PeopleValidated.xlsx");
var resultsSheet = workbook.CreateWorkSheet("Results");

resultsSheet["A1"].Value = "Row";
resultsSheet["B1"].Value = "Valid";
resultsSheet["C1"].Value = "Phone Error";
resultsSheet["D1"].Value = "Email Error";
resultsSheet["E1"].Value = "Date Error";

for (var i = 0; i < results.Count; i++)
{
    var result = results[i];
    resultsSheet[$"A{i + 2}"].Value = result.Row;
    resultsSheet[$"B{i + 2}"].Value = result.IsValid ? "Yes" : "No";
    resultsSheet[$"C{i + 2}"].Value = result.PhoneNumberErrorMessage;
    resultsSheet[$"D{i + 2}"].Value = result.EmailErrorMessage;
    resultsSheet[$"E{i + 2}"].Value = result.DateErrorMessage;
}

workbook.SaveAs(@"Spreadsheets\\PeopleValidated.xlsx");
Dim resultsSheet = workbook.CreateWorkSheet("Results")

resultsSheet("A1").Value = "Row"
resultsSheet("B1").Value = "Valid"
resultsSheet("C1").Value = "Phone Error"
resultsSheet("D1").Value = "Email Error"
resultsSheet("E1").Value = "Date Error"

For i = 0 To results.Count - 1
	Dim result = results(i)
	resultsSheet($"A{i + 2}").Value = result.Row
	resultsSheet($"B{i + 2}").Value = If(result.IsValid, "Yes", "No")
	resultsSheet($"C{i + 2}").Value = result.PhoneNumberErrorMessage
	resultsSheet($"D{i + 2}").Value = result.EmailErrorMessage
	resultsSheet($"E{i + 2}").Value = result.DateErrorMessage
Next i

workbook.SaveAs("Spreadsheets\\PeopleValidated.xlsx")
VB   C#

8. Export Data using Entity Framework

Use IronXL to export data to a database or convert an Excel spreadsheet to a database. The ExcelToDB sample reads a spreadsheet with GDP by country and then exports that data to an SQLite database. It uses EntityFramework to build the database and then export the data line by line.

Add the SQLite Entity Framework NuGet packages.

EntityFramework allows you to create a model object that can export data to the database.

public class Country
{
    [Key]
    public Guid Key { get; set; }
    public string Name { get; set; }
    public decimal GDP { get; set; }
}
public class Country
{
    [Key]
    public Guid Key { get; set; }
    public string Name { get; set; }
    public decimal GDP { get; set; }
}
Public Class Country
	<Key>
	Public Property Key() As Guid
	Public Property Name() As String
	Public Property GDP() As Decimal
End Class
VB   C#

This code configures the database context. To use a different database, install the corresponding NuGet package and find the equivalent of UseSqLite()

public class CountryContext : DbContext
{
    public DbSet<Country> Countries { get; set; }

    public CountryContext()
    {
        //TODO: Make async
        Database.EnsureCreated();
    }

    /// <summary>
    /// Configure context to use Sqlite
    /// </summary>
    /// <param name="optionsBuilder"></param>
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        var connection = new SqliteConnection($"Data Source=Country.db");
        connection.Open();

        var command = connection.CreateCommand();

        //Create the database if it doesn't already exist
        command.CommandText = $"PRAGMA foreign_keys = ON;";
        command.ExecuteNonQuery();

        optionsBuilder.UseSqlite(connection);

        base.OnConfiguring(optionsBuilder);
    }

}
public class CountryContext : DbContext
{
    public DbSet<Country> Countries { get; set; }

    public CountryContext()
    {
        //TODO: Make async
        Database.EnsureCreated();
    }

    /// <summary>
    /// Configure context to use Sqlite
    /// </summary>
    /// <param name="optionsBuilder"></param>
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        var connection = new SqliteConnection($"Data Source=Country.db");
        connection.Open();

        var command = connection.CreateCommand();

        //Create the database if it doesn't already exist
        command.CommandText = $"PRAGMA foreign_keys = ON;";
        command.ExecuteNonQuery();

        optionsBuilder.UseSqlite(connection);

        base.OnConfiguring(optionsBuilder);
    }

}
Public Class CountryContext
	Inherits DbContext

	Public Property Countries() As DbSet(Of Country)

	Public Sub New()
		'TODO: Make async
		Database.EnsureCreated()
	End Sub

	''' <summary>
	''' Configure context to use Sqlite
	''' </summary>
	''' <param name="optionsBuilder"></param>
	Protected Overrides Sub OnConfiguring(ByVal optionsBuilder As DbContextOptionsBuilder)
		Dim connection = New SqliteConnection($"Data Source=Country.db")
		connection.Open()

		Dim command = connection.CreateCommand()

		'Create the database if it doesn't already exist
		command.CommandText = $"PRAGMA foreign_keys = ON;"
		command.ExecuteNonQuery()

		optionsBuilder.UseSqlite(connection)

		MyBase.OnConfiguring(optionsBuilder)
	End Sub

End Class
VB   C#

Create a CountryContext, iterate through the range to create each record, and then SaveAsync to commit data to the database

public async Task ProcessAsync()
{
    //Get the first worksheet
    var workbook = WorkBook.Load(@"Spreadsheets\\GDP.xlsx");
    var worksheet = workbook.GetWorkSheet("GDPByCountry");

    //Create the database connection
    using (var countryContext = new CountryContext())
    {
        //Iterate through all the cells
        for (var i = 2; i <= 213; i++)
        {
            //Get the range from A-B
            var range = worksheet[$"A{i}:B{i}"].ToList();

            //Create a Country entity to be saved to the database
            var country = new Country
            {
                Name = (string)range[0].Value,
                GDP = (decimal)(double)range[1].Value
            };

            //Add the entity 
            await countryContext.Countries.AddAsync(country);
        }

        //Commit changes to the database
        await countryContext.SaveChangesAsync();
    }
}
public async Task ProcessAsync()
{
    //Get the first worksheet
    var workbook = WorkBook.Load(@"Spreadsheets\\GDP.xlsx");
    var worksheet = workbook.GetWorkSheet("GDPByCountry");

    //Create the database connection
    using (var countryContext = new CountryContext())
    {
        //Iterate through all the cells
        for (var i = 2; i <= 213; i++)
        {
            //Get the range from A-B
            var range = worksheet[$"A{i}:B{i}"].ToList();

            //Create a Country entity to be saved to the database
            var country = new Country
            {
                Name = (string)range[0].Value,
                GDP = (decimal)(double)range[1].Value
            };

            //Add the entity 
            await countryContext.Countries.AddAsync(country);
        }

        //Commit changes to the database
        await countryContext.SaveChangesAsync();
    }
}
Public Async Function ProcessAsync() As Task
	'Get the first worksheet
	Dim workbook = WorkBook.Load("Spreadsheets\\GDP.xlsx")
	Dim worksheet = workbook.GetWorkSheet("GDPByCountry")

	'Create the database connection
	Using countryContext = New CountryContext()
		'Iterate through all the cells
		For i = 2 To 213
			'Get the range from A-B
			Dim range = worksheet($"A{i}:B{i}").ToList()

			'Create a Country entity to be saved to the database
			Dim country = New Country With {
				.Name = CStr(range(0).Value),
				.GDP = CDec(CDbl(range(1).Value))
			}

			'Add the entity 
			Await countryContext.Countries.AddAsync(country)
		Next i

		'Commit changes to the database
		Await countryContext.SaveChangesAsync()
	End Using
End Function
VB   C#

Sample: ExcelToDB

9. Add Formulae to a Spreadsheet

Set formula of Cell's with the Formula property.

The code below iterates through each state and puts a percentage total in column C.

//Iterate through all rows with a value
for (var y = 2; y < i; y++)
{
    //Get the C cell
    var cell = sheet[$"C{y}"].First();

    //Set the formula for the Percentage of Total column
    cell.Formula = $"=B{y}/B{i}";
}
//Iterate through all rows with a value
for (var y = 2; y < i; y++)
{
    //Get the C cell
    var cell = sheet[$"C{y}"].First();

    //Set the formula for the Percentage of Total column
    cell.Formula = $"=B{y}/B{i}";
}
'Iterate through all rows with a value
Dim y = 2
Do While y < i
	'Get the C cell
	Dim cell = sheet($"C{y}").First()

	'Set the formula for the Percentage of Total column
	cell.Formula = $"=B{y}/B{i}"
	y += 1
Loop
VB   C#

Sample: AddFormulaeProcessor

10. Download Data from an API to Spreadsheet

The following call makes a REST call with RestClient.Net. It downloads JSON and converts it into a "List" of the type RestCountry. It is then easy to iterate through each country and save the data from the REST API to an Excel spreadsheet.

var client = new Client(new Uri("https://restcountries.eu/rest/v2/"));
List<RestCountry> countries = await client.GetAsync<List<RestCountry>>();
var client = new Client(new Uri("https://restcountries.eu/rest/v2/"));
List<RestCountry> countries = await client.GetAsync<List<RestCountry>>();
Dim client = New Client(New Uri("https://restcountries.eu/rest/v2/"))
Dim countries As List(Of RestCountry) = Await client.GetAsync(Of List(Of RestCountry))()
VB   C#

Sample: ApiToExcel

This is what the API JSON data looks like.

The following code iterates through the countries and sets the Name, Population, Region, NumericCode, and Top 3 Languages in the spreadsheet.

for (var i = 2; i < countries.Count; i++)
{
    var country = countries[i];

    //Set the basic values
    worksheet[$"A{i}"].Value = country.name;
    worksheet[$"B{i}"].Value = country.population;
    worksheet[$"G{i}"].Value = country.region;
    worksheet[$"H{i}"].Value = country.numericCode;

    //Iterate through languages
    for (var x = 0; x < 3; x++)
    {
        if (x > (country.languages.Count - 1)) break;

        var language = country.languages[x];

        //Get the letter for the column
        var columnLetter = GetColumnLetter(4 + x);

        //Set the language name
        worksheet[$"{columnLetter}{i}"].Value = language.name;
    }
}
for (var i = 2; i < countries.Count; i++)
{
    var country = countries[i];

    //Set the basic values
    worksheet[$"A{i}"].Value = country.name;
    worksheet[$"B{i}"].Value = country.population;
    worksheet[$"G{i}"].Value = country.region;
    worksheet[$"H{i}"].Value = country.numericCode;

    //Iterate through languages
    for (var x = 0; x < 3; x++)
    {
        if (x > (country.languages.Count - 1)) break;

        var language = country.languages[x];

        //Get the letter for the column
        var columnLetter = GetColumnLetter(4 + x);

        //Set the language name
        worksheet[$"{columnLetter}{i}"].Value = language.name;
    }
}
For i = 2 To countries.Count - 1
	Dim country = countries(i)

	'Set the basic values
	worksheet($"A{i}").Value = country.name
	worksheet($"B{i}").Value = country.population
	worksheet($"G{i}").Value = country.region
	worksheet($"H{i}").Value = country.numericCode

	'Iterate through languages
	For x = 0 To 2
		If x > (country.languages.Count - 1) Then
			Exit For
		End If

		Dim language = country.languages(x)

		'Get the letter for the column
		Dim columnLetter = GetColumnLetter(4 + x)

		'Set the language name
		worksheet($"{columnLetter}{i}").Value = language.name
	Next x
Next i
VB   C#

Object Reference and Resources

You may also find the IronXL class documentation within the Object Reference of great value.

In addition, there are other tutorials which may shed light in other aspects of IronXL.Excel including Creating, Opening, Writing Editing, Saving and Exporting XLS, XLSX and CSV files without using Excel Interop..

Tutorial Quick Access

Download this Tutorial as C# Source Code

The full free C# for Excel Source Code for this tutorial is available to download as a zipped Visual Studio 2017 project file.

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The source code for this project is available in C# and VB.NET on GitHub.

Use this code as an easy way to get up and running in just a few minutes. The project is saved as a Microsoft Visual Studio 2017 project, but is compatible with any .NET IDE.

How to Read Excel File in C# on GitHub

View the Object Reference

Explore the Object Reference for IronXL, outlining the details of all of IronXL’s features, namespaces, classes, methods fields and enums.

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.Net Solution Director working with Microsoft Excel document IO

Christian Findlay

Software Development Team Lead

Christian builds software for the health industry and leads up a team. Christian has years of experience integrating with systems of all kinds. IronXL allows Christian to import and manipulate data from different sources to automate repetitive tasks and validate input data from 3rd party sources.

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