How to Read Excel Files in C# (Developer Tutorial)

using IronXL;
using System;
using System.Linq;

// Load the workbook from the specified file
WorkBook workBook = WorkBook.Load("test.xlsx");
WorkSheet workSheet = workBook.WorkSheets.First();

// Select cell A2 and get its integer value
int cellValue = workSheet["A2"].IntValue;

// Output the value of cell A2
Console.WriteLine("The integer value of cell A2 is: " + cellValue);

// Iterate over the cells in the range A2:A10
foreach (var cell in workSheet["A2:A10"])
{
    // Print the address and text value of each cell
    Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text);
}

// Advanced Operations
// Calculate the sum of the values in the range A2:A10
decimal sum = workSheet["A2:A10"]
    .Select(cell => cell.DecimalValue) // Convert each cell value to decimal
    .Sum(); // Sum all the decimal values

// Calculate the maximum value in the range A2:A10 using Linq
decimal max = workSheet["A2:A10"]
    .Max(c => c.DecimalValue); // Find the maximum decimal value in the range

Console.WriteLine("The sum of the values in the range A2:A10 is: " + sum);
Console.WriteLine("The maximum value in the range A2:A10 is: " + max);

Imports IronXL

Imports System

Imports System.Linq



' Load the workbook from the specified file

Private workBook As WorkBook = WorkBook.Load("test.xlsx")

Private workSheet As WorkSheet = workBook.WorkSheets.First()



' Select cell A2 and get its integer value

Private cellValue As Integer = workSheet("A2").IntValue



' Output the value of cell A2

Console.WriteLine("The integer value of cell A2 is: " & cellValue)



' Iterate over the cells in the range A2:A10

For Each cell In workSheet("A2:A10")

	' Print the address and text value of each cell

	Console.WriteLine("Cell {0} has value '{1}'", cell.AddressString, cell.Text)

Next cell



' Advanced Operations

' Calculate the sum of the values in the range A2:A10

Dim sum As Decimal = workSheet("A2:A10").Select(Function(cell) cell.DecimalValue).Sum() ' Sum all the decimal values



' Calculate the maximum value in the range A2:A10 using Linq

Dim max As Decimal = workSheet("A2:A10").Max(Function(c) c.DecimalValue) ' Find the maximum decimal value in the range



Console.WriteLine("The sum of the values in the range A2:A10 is: " & sum)

Console.WriteLine("The maximum value in the range A2:A10 is: " & max)

// Import necessary libraries
using System;
using IronXL;

// Initially set WorkBook object to null. Loading will be attempted in a try-catch block.
WorkBook workBook = null;

try
{
    // Attempt to load the workbook from the specified file path.
    // This is a relative path, adjust it according to where the Excel file is located.
    workBook = WorkBook.Load(@"Spreadsheets\GDP.xlsx");

    // If the workbook is loaded successfully, print a confirmation message.
    Console.WriteLine("Workbook loaded successfully.");

    // You can now perform further operations on the workbook.
    // For example, accessing a specific worksheet:
    WorkSheet sheet = workBook.GetWorkSheet("Sheet1");

    // Perform operations on the sheet
    // Example: print the value of a specific cell (for illustration purposes).
    Console.WriteLine("Value of A1: " + sheet["A1"].StringValue);

    // Add more operations as needed...
}
catch (Exception ex)
{
    // If an error occurs during the loading of the workbook, print out the exception details.
    Console.WriteLine("An error occurred while loading the workbook: " + ex.Message);
}

// Important note: Make sure that the IronXL library is properly included in the project.
// This can be done through a NuGet package manager. The IronXL library allows for 
// interaction with Excel files (.xlsx, .xls, etc.), facilitating the loading, reading, 
// and manipulation of spreadsheet data.

' Import necessary libraries

Imports System

Imports IronXL



' Initially set WorkBook object to null. Loading will be attempted in a try-catch block.

Private workBook As WorkBook = Nothing



Try

	' Attempt to load the workbook from the specified file path.

	' This is a relative path, adjust it according to where the Excel file is located.

	workBook = WorkBook.Load("Spreadsheets\GDP.xlsx")



	' If the workbook is loaded successfully, print a confirmation message.

	Console.WriteLine("Workbook loaded successfully.")



	' You can now perform further operations on the workbook.

	' For example, accessing a specific worksheet:

	Dim sheet As WorkSheet = workBook.GetWorkSheet("Sheet1")



	' Perform operations on the sheet

	' Example: print the value of a specific cell (for illustration purposes).

	Console.WriteLine("Value of A1: " & sheet("A1").StringValue)



	' Add more operations as needed...

Catch ex As Exception

	' If an error occurs during the loading of the workbook, print out the exception details.

	Console.WriteLine("An error occurred while loading the workbook: " & ex.Message)

End Try



' Important note: Make sure that the IronXL library is properly included in the project.

' This can be done through a NuGet package manager. The IronXL library allows for 

' interaction with Excel files (.xlsx, .xls, etc.), facilitating the loading, reading, 

' and manipulation of spreadsheet data.

// Assume that we are working with a library that deals with workbooks and worksheets.
// This code snippet demonstrates how to find a worksheet by its name within a specific workbook object.

// Ensure that the 'workBook' object is properly instantiated and not null before attempting to retrieve a worksheet.
if (workBook == null)
{
    throw new ArgumentNullException(nameof(workBook), "The workbook must be instantiated and cannot be null.");
}

// Use the correct method name and check the return value for handling cases where the worksheet might not be found.
WorkSheet workSheet = workBook.GetWorksheet("GDPByCountry");

// The line above tries to obtain a worksheet named "GDPByCountry" from a workbook object named 'workBook'.
// It assumes the existence of 'workBook', which is an instantiated object with a method 'GetWorksheet' 
// that returns a worksheet object by its name.
//
// Potential issues to consider in real-world scenarios:
// 1. Confirm that the 'GetWorksheet' method is correctly spelled with the appropriate case sensitivity.
//    This requires checking the documentation or API signature from the library being used.
// 2. Ensure that 'WorkSheet' type is correctly spelled and used; this is also case-sensitive.
// 3. The method may return null or throw an exception if the worksheet is not found.
//    Implement error handling to gracefully handle such situations:
//
// Example of error handling:
if (workSheet == null)
{
    // Handle the case where the worksheet was not found.
    Console.WriteLine("Worksheet 'GDPByCountry' not found in the workbook.");
}
else
{
    // Proceed with operations on the found worksheet.
    Console.WriteLine("Worksheet 'GDPByCountry' successfully retrieved.");
}

' Assume that we are working with a library that deals with workbooks and worksheets.

' This code snippet demonstrates how to find a worksheet by its name within a specific workbook object.



' Ensure that the 'workBook' object is properly instantiated and not null before attempting to retrieve a worksheet.

If workBook Is Nothing Then

	Throw New ArgumentNullException(NameOf(workBook), "The workbook must be instantiated and cannot be null.")

End If



' Use the correct method name and check the return value for handling cases where the worksheet might not be found.

Dim workSheet As WorkSheet = workBook.GetWorksheet("GDPByCountry")



' The line above tries to obtain a worksheet named "GDPByCountry" from a workbook object named 'workBook'.

' It assumes the existence of 'workBook', which is an instantiated object with a method 'GetWorksheet' 

' that returns a worksheet object by its name.

'

' Potential issues to consider in real-world scenarios:

' 1. Confirm that the 'GetWorksheet' method is correctly spelled with the appropriate case sensitivity.

'    This requires checking the documentation or API signature from the library being used.

' 2. Ensure that 'WorkSheet' type is correctly spelled and used; this is also case-sensitive.

' 3. The method may return null or throw an exception if the worksheet is not found.

'    Implement error handling to gracefully handle such situations:

'

' Example of error handling:

If workSheet Is Nothing Then

	' Handle the case where the worksheet was not found.

	Console.WriteLine("Worksheet 'GDPByCountry' not found in the workbook.")

Else

	' Proceed with operations on the found worksheet.

	Console.WriteLine("Worksheet 'GDPByCountry' successfully retrieved.")

End If

using System;

// Namespace declaration for organizing classes related to Excel Workbook examples
namespace ExcelWorkbookExample
{
    /// <summary>
    /// A simple example demonstrating how to create a workbook in XLSX format.
    /// Assumes that a library like EPPlus or a similar one is being used for Excel file handling,
    /// since .NET does not natively support Excel file creation without a third-party library.
    /// </summary>
    public class ExcelWorkbookCreator
    {
        // Method to create an Excel workbook, though the actual implementation 
        // of Excel library code is only demonstrated conceptually here.
        public void CreateWorkbook()
        {
            // This method assumes the use of a library, such as EPPlus, to manage Excel files.
            // Actual operations such as adding data or saving the file are done through that library's API.
            
            // Placeholder for the Excel library's workbook creation method
            // e.g., for EPPlus, you would initialize an ExcelPackage and add a Workbook.
            // ExcelPackage package = new ExcelPackage();
            // var workBook = package.Workbook;

            Console.WriteLine("Workbook created successfully in XLSX format.");
        }
    }
    
    // Main class and method to demonstrate workbook creation.
    // In a real usage scenario, you would probably remove this and call the method from another context.
    public static class Program
    {
        public static void Main()
        {
            // Instantiation of the ExcelWorkbookCreator class to demonstrate the workbook creation process.
            ExcelWorkbookCreator creator = new ExcelWorkbookCreator();
            creator.CreateWorkbook();
        }
    }
}

Imports System



' Namespace declaration for organizing classes related to Excel Workbook examples

Namespace ExcelWorkbookExample

	''' <summary>

	''' A simple example demonstrating how to create a workbook in XLSX format.

	''' Assumes that a library like EPPlus or a similar one is being used for Excel file handling,

	''' since .NET does not natively support Excel file creation without a third-party library.

	''' </summary>

	Public Class ExcelWorkbookCreator

		' Method to create an Excel workbook, though the actual implementation 

		' of Excel library code is only demonstrated conceptually here.

		Public Sub CreateWorkbook()

			' This method assumes the use of a library, such as EPPlus, to manage Excel files.

			' Actual operations such as adding data or saving the file are done through that library's API.



			' Placeholder for the Excel library's workbook creation method

			' e.g., for EPPlus, you would initialize an ExcelPackage and add a Workbook.

			' ExcelPackage package = new ExcelPackage();

			' var workBook = package.Workbook;



			Console.WriteLine("Workbook created successfully in XLSX format.")

		End Sub

	End Class



	' Main class and method to demonstrate workbook creation.

	' In a real usage scenario, you would probably remove this and call the method from another context.

	Public Module Program

		Public Sub Main()

			' Instantiation of the ExcelWorkbookCreator class to demonstrate the workbook creation process.

			Dim creator As New ExcelWorkbookCreator()

			creator.CreateWorkbook()

		End Sub

	End Module

End Namespace

// This code assumes that a workbook object has been initialized elsewhere in the application.
// It retrieves a worksheet named "GDPByCountry" from the workbook.

// Declare a WorkSheet object to hold the retrieved worksheet named "GDPByCountry."
// 'workBook' must be a valid instance of a class containing the 'GetWorkSheet' method,
// capable of returning a worksheet by its name.
WorkSheet workSheet = workBook.GetWorkSheet("GDPByCountry");

// Note:
// - Ensure that 'workBook' is a correctly initialized instance of a class that provides 
//   the following method:
//   public WorkSheet GetWorkSheet(string sheetName)
//
// - Verify that there is indeed a worksheet named "GDPByCountry" within the workbook
//   to avoid runtime errors related to null references or similar issues.

' This code assumes that a workbook object has been initialized elsewhere in the application.

' It retrieves a worksheet named "GDPByCountry" from the workbook.



' Declare a WorkSheet object to hold the retrieved worksheet named "GDPByCountry."

' 'workBook' must be a valid instance of a class containing the 'GetWorkSheet' method,

' capable of returning a worksheet by its name.

Dim workSheet As WorkSheet = workBook.GetWorkSheet("GDPByCountry")



' Note:

' - Ensure that 'workBook' is a correctly initialized instance of a class that provides 

'   the following method:

'   public WorkSheet GetWorkSheet(string sheetName)

'

' - Verify that there is indeed a worksheet named "GDPByCountry" within the workbook

'   to avoid runtime errors related to null references or similar issues.

using IronXL;

// Load the existing Excel workbook
WorkBook workBook = WorkBook.Load("test.xlsx");

// Retrieve the default worksheet from the loaded workbook
WorkSheet workSheet = workBook.DefaultWorkSheet;

// Access the cell at B1 location on the worksheet
// The 'First()' method ensures that we are accessing the first cell, 
// which is necessary especially when dealing with potential ranges.
IronXL.Cell cell = workSheet["B1"].First();

// At this point, 'cell' contains the cell at position B1 on the default worksheet.
// Further operations can be performed on 'cell', like reading its value or modifying it.
   
   // Example:
   // var cellValue = cell.Value;  // To read the value of the cell
   // cell.Value = "New Value";    // To write a new value into the cell

// Save changes to the workbook if any modifications are made
// workBook.Save();

Imports IronXL



' Load the existing Excel workbook

Private workBook As WorkBook = WorkBook.Load("test.xlsx")



' Retrieve the default worksheet from the loaded workbook

Private workSheet As WorkSheet = workBook.DefaultWorkSheet



' Access the cell at B1 location on the worksheet

' The 'First()' method ensures that we are accessing the first cell, 

' which is necessary especially when dealing with potential ranges.

Private cell As IronXL.Cell = workSheet("B1").First()



' At this point, 'cell' contains the cell at position B1 on the default worksheet.

' Further operations can be performed on 'cell', like reading its value or modifying it.



   ' Example:

   ' var cellValue = cell.Value;  // To read the value of the cell

   ' cell.Value = "New Value";    // To write a new value into the cell



' Save changes to the workbook if any modifications are made

' workBook.Save();

// Using IronXL library to interact with Excel files is assumed.
// This code demonstrates basic operations like reading from and writing to an Excel worksheet using IronXL.

// IronXL namespace for Excel operations should be used
using IronXL;

// Assuming `workSheet` is a valid Worksheet object initialized elsewhere in the code.
// The `workSheet` object must be properly instantiated before this code is executed.
var workSheet = WorkBook.Load("path/to/excel/file.xlsx").GetWorkSheet("SheetName");

// Retrieve the first cell in the specified range, "B1"
IronXL.Cell cell = workSheet["B1"];

// Read the value of the cell as a string
string value = cell.StringValue;

// Output the current value of the cell to the console
Console.WriteLine("Original Cell Value: " + value);

// Write a new value to the cell
cell.Value = 10.3289;

// Output the updated cell value to the console
Console.WriteLine("Updated Cell Value: " + cell.StringValue);

// Note: Ensure that the IronXL library is correctly referenced in your project 
// and that you have the necessary licenses to use the library functions.

' Using IronXL library to interact with Excel files is assumed.

' This code demonstrates basic operations like reading from and writing to an Excel worksheet using IronXL.



' IronXL namespace for Excel operations should be used

Imports IronXL



' Assuming `workSheet` is a valid Worksheet object initialized elsewhere in the code.

' The `workSheet` object must be properly instantiated before this code is executed.

Private workSheet = WorkBook.Load("path/to/excel/file.xlsx").GetWorkSheet("SheetName")



' Retrieve the first cell in the specified range, "B1"

Private cell As IronXL.Cell = workSheet("B1")



' Read the value of the cell as a string

Private value As String = cell.StringValue



' Output the current value of the cell to the console

Console.WriteLine("Original Cell Value: " & value)



' Write a new value to the cell

cell.Value = 10.3289



' Output the updated cell value to the console

Console.WriteLine("Updated Cell Value: " & cell.StringValue)



' Note: Ensure that the IronXL library is correctly referenced in your project 

' and that you have the necessary licenses to use the library functions.

// This code snippet assumes that we're working with an Excel worksheet.
// It tries to create a Range object corresponding to the cells D2 through D101 in the worksheet.

// Assuming 'workSheet' is a properly initialized Excel worksheet object in your program
// Here, we create a Range object that represents the range of cells from D2 to D101 in the worksheet.
Range range = workSheet.Range["D2:D101"];

// Explanation of the code:
// - The 'Range' property of the 'workSheet' object is accessed to get the desired cells.
// - 'Range' is a part of the Excel interop library that allows you to define a range of cells.

' This code snippet assumes that we're working with an Excel worksheet.

' It tries to create a Range object corresponding to the cells D2 through D101 in the worksheet.



' Assuming 'workSheet' is a properly initialized Excel worksheet object in your program

' Here, we create a Range object that represents the range of cells from D2 to D101 in the worksheet.

Dim range As Range = workSheet.Range("D2:D101")



' Explanation of the code:

' - The 'Range' property of the 'workSheet' object is accessed to get the desired cells.

' - 'Range' is a part of the Excel interop library that allows you to define a range of cells.

// Define the PersonValidationResult class to store validation results for each row
public class PersonValidationResult
{
    public int Row { get; set; } // The row number being validated
    public string PhoneNumberErrorMessage { get; set; } // Error message for phone number validation
    public string EmailErrorMessage { get; set; } // Error message for email validation
    public string DateErrorMessage { get; set; } // Error message for date validation
}

// Assuming this code is part of a larger method or context where 'results' and 'worksheet' are defined
// 'results' is a list to store validation results for each row
var results = new List<PersonValidationResult>();

// 'workSheet' is an instance of an EPPlus ExcelWorksheet or similar object that you are working with
var phoneNumberUtil = PhoneNumberUtil.GetInstance(); // Assuming Google libphonenumber is being used for phone validation

// Iterate through the rows of the spreadsheet from row 2 to 101
for (var y = 2; y <= 101; y++)
{
    // Initialize a new validation result object for each row
    var result = new PersonValidationResult { Row = y };
    results.Add(result);

    // Get all cells for the person in columns A to E for the current row
    // EPPlus may return a range, ensure conversion to a list
    var cells = workSheet.Cells[$"A{y}:E{y}"].ToArray();

    // Validate the phone number in column B (index 1 in 0-based array)
    var phoneNumber = cells[1].Text; // Using Text property in case of number formatting issues
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, phoneNumber);

    // Validate the email address in column D (index 3 in 0-based array)
    result.EmailErrorMessage = ValidateEmailAddress(cells[3].Text);

    // Get and validate the raw date in column E (index 4 in 0-based array)
    var rawDate = cells[4].Text;
    result.DateErrorMessage = ValidateDate(rawDate);
}

// Define helper functions
string ValidatePhoneNumber(PhoneNumberUtil phoneNumberUtil, string phoneNumber)
{
    // Implement the phone number validation logic here using phoneNumberUtil
    // Return an error message if validation fails, else return null or empty string
    // Example placeholder logic:
    return ""; // placeholder
}

string ValidateEmailAddress(string emailAddress)
{
    // Implement the email address validation logic here
    // Return an error message if validation fails, else return null or empty string
    // Example placeholder logic:
    return ""; // placeholder
}

string ValidateDate(string rawDate)
{
    // Implement the date validation logic here
    // Return an error message if validation fails, else return null or empty string
    // Example placeholder logic:
    return ""; // placeholder
}

' Define the PersonValidationResult class to store validation results for each row

Public Class PersonValidationResult

	Public Property Row() As Integer ' -  The row number being validated

	Public Property PhoneNumberErrorMessage() As String ' -  Error message for phone number validation

	Public Property EmailErrorMessage() As String ' -  Error message for email validation

	Public Property DateErrorMessage() As String ' -  Error message for date validation

End Class



' Assuming this code is part of a larger method or context where 'results' and 'worksheet' are defined

' 'results' is a list to store validation results for each row

Private results = New List(Of PersonValidationResult)()



' 'workSheet' is an instance of an EPPlus ExcelWorksheet or similar object that you are working with

Private phoneNumberUtil = PhoneNumberUtil.GetInstance() ' Assuming Google libphonenumber is being used for phone validation



' Iterate through the rows of the spreadsheet from row 2 to 101

For y = 2 To 101

	' Initialize a new validation result object for each row

	Dim result = New PersonValidationResult With {.Row = y}

	results.Add(result)



	' Get all cells for the person in columns A to E for the current row

	' EPPlus may return a range, ensure conversion to a list

	Dim cells = workSheet.Cells($"A{y}:E{y}").ToArray()



	' Validate the phone number in column B (index 1 in 0-based array)

	Dim phoneNumber = cells(1).Text ' Using Text property in case of number formatting issues

	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, phoneNumber)



	' Validate the email address in column D (index 3 in 0-based array)

	result.EmailErrorMessage = ValidateEmailAddress(cells(3).Text)



	' Get and validate the raw date in column E (index 4 in 0-based array)

	Dim rawDate = cells(4).Text

	result.DateErrorMessage = ValidateDate(rawDate)

Next y



' Define helper functions

'INSTANT VB TODO TASK: Local functions are not converted by Instant VB:

'string ValidatePhoneNumber(PhoneNumberUtil phoneNumberUtil, string phoneNumber)

'{

'	' Implement the phone number validation logic here using phoneNumberUtil

'	' Return an error message if validation fails, else return null or empty string

'	' Example placeholder logic:

'	Return ""; ' placeholder

'}



'INSTANT VB TODO TASK: Local functions are not converted by Instant VB:

'string ValidateEmailAddress(string emailAddress)

'{

'	' Implement the email address validation logic here

'	' Return an error message if validation fails, else return null or empty string

'	' Example placeholder logic:

'	Return ""; ' placeholder

'}



'INSTANT VB TODO TASK: Local functions are not converted by Instant VB:

'string ValidateDate(string rawDate)

'{

'	' Implement the date validation logic here

'	' Return an error message if validation fails, else return null or empty string

'	' Example placeholder logic:

'	Return ""; ' placeholder

'}

// This code block iterates through certain rows in an Excel worksheet and sets a formula for each cell in column C.
// The formula calculates the percentage of the total by dividing the value in column B of the current row 
// by the value in column B of the last row. It assumes that 'i' is defined as the boundary row index, 
// and 'workSheet' is a previously initialized worksheet object.

for (var y = 2; y < i; y++)
{
    // Access the first cell in column C of the current row
    Cell cell = workSheet.Cells[$"C{y}"].First();  // Assumes 'Cells' is a valid collection

    // Set a formula to the cell that calculates the percentage of the total using the values in column B.
    cell.Formula = $"=B{y}/B{i}";  // Formula is calculated as current row value (B{y}) divided by last row value (B{i})
}

' This code block iterates through certain rows in an Excel worksheet and sets a formula for each cell in column C.

' The formula calculates the percentage of the total by dividing the value in column B of the current row 

' by the value in column B of the last row. It assumes that 'i' is defined as the boundary row index, 

' and 'workSheet' is a previously initialized worksheet object.



Dim y = 2

Do While y < i

	' Access the first cell in column C of the current row

	Dim cell As Cell = workSheet.Cells($"C{y}").First() ' Assumes 'Cells' is a valid collection



	' Set a formula to the cell that calculates the percentage of the total using the values in column B.

	cell.Formula = $"=B{y}/B{i}" ' Formula is calculated as current row value (B{y}) divided by last row value (B{i})

	y += 1

Loop

// This code iterates through rows 2 to 101 of an Excel worksheet, validating data in each row.
// It checks phone numbers, email addresses, and dates, storing any validation error messages found.

for (var i = 2; i <= 101; i++)
{
    // Create a new validation result for each row.
    // The row number is stored in the result to track which row any errors occur in.
    var result = new PersonValidationResult { Row = i };
    results.Add(result);

    // Get all cells for the individual in the current row using a range from columns A to E.
    // The cells are expected to contain relevant data used for validation.
    var cells = worksheet[$"A{i}:E{i}"].ToList();

    // Validate the phone number located in column B (index 1).
    // Conversion of the cell value to a string may be necessary if the value is not naturally a string.
    var phoneNumber = cells[1].Value;
    result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, (string)phoneNumber);

    // Validate the email address located in column D (index 3).
    // The value can directly be cast to a string as it is expected to be a string type cell.
    var emailValue = cells[3].Value as string;
    result.EmailErrorMessage = ValidateEmailAddress(emailValue);

    // Validate the date located in column E (index 4).
    // Dates are retrieved as strings for validation purposes.
    var rawDate = cells[4].Value as string;
    result.DateErrorMessage = ValidateDate(rawDate);
}

' This code iterates through rows 2 to 101 of an Excel worksheet, validating data in each row.

' It checks phone numbers, email addresses, and dates, storing any validation error messages found.



For i = 2 To 101

	' Create a new validation result for each row.

	' The row number is stored in the result to track which row any errors occur in.

	Dim result = New PersonValidationResult With {.Row = i}

	results.Add(result)



	' Get all cells for the individual in the current row using a range from columns A to E.

	' The cells are expected to contain relevant data used for validation.

	Dim cells = worksheet($"A{i}:E{i}").ToList()



	' Validate the phone number located in column B (index 1).

	' Conversion of the cell value to a string may be necessary if the value is not naturally a string.

	Dim phoneNumber = cells(1).Value

	result.PhoneNumberErrorMessage = ValidatePhoneNumber(phoneNumberUtil, CStr(phoneNumber))



	' Validate the email address located in column D (index 3).

	' The value can directly be cast to a string as it is expected to be a string type cell.

	Dim emailValue = TryCast(cells(3).Value, String)

	result.EmailErrorMessage = ValidateEmailAddress(emailValue)



	' Validate the date located in column E (index 4).

	' Dates are retrieved as strings for validation purposes.

	Dim rawDate = TryCast(cells(4).Value, String)

	result.DateErrorMessage = ValidateDate(rawDate)

Next i

// Ensure the workbook object 'workBook' and the collection of results 'results' are available in the top-level scope

// Create a worksheet named "Results" in the workbook.
var resultsSheet = workBook.CreateWorksheet("Results");

// Set headers for each column in the first row.
resultsSheet["A1"].Value = "Row";             // Column A: Row Number
resultsSheet["B1"].Value = "Valid";           // Column B: Valid Entry Indicator
resultsSheet["C1"].Value = "Phone Error";     // Column C: Phone Number Error Message
resultsSheet["D1"].Value = "Email Error";     // Column D: Email Error Message
resultsSheet["E1"].Value = "Date Error";      // Column E: Date Error Message

// Loop through the list of results to populate the worksheet.
for (var i = 0; i < results.Count; i++)
{
    var result = results[i];

    // Set the row number in the first column.
    resultsSheet[$"A{i + 2}"].Value = i + 1;

    // Indicate if the result is valid in the second column.
    resultsSheet[$"B{i + 2}"].Value = result.IsValid ? "Yes" : "No";

    // Fill in the error messages for phone, email, and date in the respective columns.
    resultsSheet[$"C{i + 2}"].Value = string.IsNullOrEmpty(result.PhoneNumberErrorMessage) ? "" : result.PhoneNumberErrorMessage;
    resultsSheet[$"D{i + 2}"].Value = string.IsNullOrEmpty(result.EmailErrorMessage) ? "" : result.EmailErrorMessage;
    resultsSheet[$"E{i + 2}"].Value = string.IsNullOrEmpty(result.DateErrorMessage) ? "" : result.DateErrorMessage;
}

// Save the workbook to the specified path.
workBook.SaveAs(@"Spreadsheets\PeopleValidated.xlsx");

' Ensure the workbook object 'workBook' and the collection of results 'results' are available in the top-level scope



' Create a worksheet named "Results" in the workbook.

Dim resultsSheet = workBook.CreateWorksheet("Results")



' Set headers for each column in the first row.

resultsSheet("A1").Value = "Row" ' Column A: Row Number

resultsSheet("B1").Value = "Valid" ' Column B: Valid Entry Indicator

resultsSheet("C1").Value = "Phone Error" ' Column C: Phone Number Error Message

resultsSheet("D1").Value = "Email Error" ' Column D: Email Error Message

resultsSheet("E1").Value = "Date Error" ' Column E: Date Error Message



' Loop through the list of results to populate the worksheet.

For i = 0 To results.Count - 1

	Dim result = results(i)



	' Set the row number in the first column.

	resultsSheet($"A{i + 2}").Value = i + 1



	' Indicate if the result is valid in the second column.

	resultsSheet($"B{i + 2}").Value = If(result.IsValid, "Yes", "No")



	' Fill in the error messages for phone, email, and date in the respective columns.

	resultsSheet($"C{i + 2}").Value = If(String.IsNullOrEmpty(result.PhoneNumberErrorMessage), "", result.PhoneNumberErrorMessage)

	resultsSheet($"D{i + 2}").Value = If(String.IsNullOrEmpty(result.EmailErrorMessage), "", result.EmailErrorMessage)

	resultsSheet($"E{i + 2}").Value = If(String.IsNullOrEmpty(result.DateErrorMessage), "", result.DateErrorMessage)

Next i



' Save the workbook to the specified path.

workBook.SaveAs("Spreadsheets\PeopleValidated.xlsx")

using System;
using System.ComponentModel.DataAnnotations;

// This class represents a Country entity with properties for Key, Name, and GDP.
public class Country
{
    // Key attribute is used to annotate the primary key of the entity.
    [Key]
    public Guid Key { get; set; }

    // The name of the country.
    public string Name { get; set; }

    // The GDP (Gross Domestic Product) value of the country.
    public decimal GDP { get; set; }
}

Imports System

Imports System.ComponentModel.DataAnnotations



' This class represents a Country entity with properties for Key, Name, and GDP.

Public Class Country

	' Key attribute is used to annotate the primary key of the entity.

	<Key>

	Public Property Key() As Guid



	' The name of the country.

	Public Property Name() As String



	' The GDP (Gross Domestic Product) value of the country.

	Public Property GDP() As Decimal

End Class

using System;
using Microsoft.EntityFrameworkCore;
using Microsoft.Data.Sqlite;

/// <summary>
/// Represents a country entity.
/// </summary>
public class Country
{
    /// <summary>
    /// Gets or sets the unique identifier for the country.
    /// </summary>
    public int Id { get; set; }

    /// <summary>
    /// Gets or sets the name of the country.
    /// </summary>
    public string Name { get; set; }
}

/// <summary>
/// Represents the database context for accessing the Country database.
/// </summary>
public class CountryContext : DbContext
{
    /// <summary>
    /// Gets or sets the DbSet of countries.
    /// </summary>
    public DbSet<Country> Countries { get; set; }

    /// <summary>
    /// Initializes a new instance of the <see cref="CountryContext"/> class.
    /// Ensures the database is created.
    /// </summary>
    public CountryContext()
    {
        // Synchronously ensures that the database for the context is created.
        Database.EnsureCreatedAsync().Wait();
    }

    /// <inheritdoc />
    /// <summary>
    /// Configures the database context to use SQLite.
    /// </summary>
    /// <param name="optionsBuilder">The options builder being used for configuration.</param>
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        // Establish a connection to an SQLite database.
        var connection = new SqliteConnection("Data Source=Country.db");
        connection.Open();

        // Configure the context to use SQLite with the opened connection.
        optionsBuilder.UseSqlite(connection);

        // Enforce foreign key constraints in SQLite.
        using (var command = connection.CreateCommand())
        {
            command.CommandText = "PRAGMA foreign_keys = ON;";
            command.ExecuteNonQuery();
        }

        // It is good practice to call the base implementation.
        base.OnConfiguring(optionsBuilder);
    }
}

Imports System

Imports Microsoft.EntityFrameworkCore

Imports Microsoft.Data.Sqlite



''' <summary>

''' Represents a country entity.

''' </summary>

Public Class Country

	''' <summary>

	''' Gets or sets the unique identifier for the country.

	''' </summary>

	Public Property Id() As Integer



	''' <summary>

	''' Gets or sets the name of the country.

	''' </summary>

	Public Property Name() As String

End Class



''' <summary>

''' Represents the database context for accessing the Country database.

''' </summary>

Public Class CountryContext

	Inherits DbContext



	''' <summary>

	''' Gets or sets the DbSet of countries.

	''' </summary>

	Public Property Countries() As DbSet(Of Country)



	''' <summary>

	''' Initializes a new instance of the <see cref="CountryContext"/> class.

	''' Ensures the database is created.

	''' </summary>

	Public Sub New()

		' Synchronously ensures that the database for the context is created.

		Database.EnsureCreatedAsync().Wait()

	End Sub



	''' <inheritdoc />

	''' <summary>

	''' Configures the database context to use SQLite.

	''' </summary>

	''' <param name="optionsBuilder">The options builder being used for configuration.</param>

	Protected Overrides Sub OnConfiguring(ByVal optionsBuilder As DbContextOptionsBuilder)

		' Establish a connection to an SQLite database.

		Dim connection = New SqliteConnection("Data Source=Country.db")

		connection.Open()



		' Configure the context to use SQLite with the opened connection.

		optionsBuilder.UseSqlite(connection)



		' Enforce foreign key constraints in SQLite.

		Using command = connection.CreateCommand()

			command.CommandText = "PRAGMA foreign_keys = ON;"

			command.ExecuteNonQuery()

		End Using



		' It is good practice to call the base implementation.

		MyBase.OnConfiguring(optionsBuilder)

	End Sub

End Class

using System.Threading.Tasks;
using IronXL;
using Microsoft.EntityFrameworkCore;

// This method processes an Excel worksheet to extract country names and GDP values,
// then saves them into a database.
public async Task ProcessAsync()
{
    try
    {
        // Load the workbook from the specified file path.
        var workbook = WorkBook.Load(@"Spreadsheets\GDP.xlsx");

        // Get the worksheet named "GDPByCountry" from the workbook.
        var worksheet = workbook.GetWorkSheet("GDPByCountry");

        // Create a database context for interacting with the Country database.
        using (var countryContext = new CountryContext())
        {
            // Iterate through each row of the worksheet from row 2 to 213.
            for (var i = 2; i <= 213; i++)
            {
                // Fetch the range of cells from columns A to B in the current row.
                var range = worksheet[$"A{i}:B{i}"].ToList();

                // Ensure there are at least two cells in the range.
                if (range.Count < 2)
                {
                    continue; // Skip rows that do not have both columns filled.
                }

                // Create a Country entity object to be stored in the database.
                var country = new Country
                {
                    // Extract and cast the value from the first cell as a string for the country's name.
                    Name = range[0]?.ToString()?.Trim(),

                    // Extract and cast the value from the second cell as a decimal for the country's GDP.
                    // Handles potential null by using safe casting and null-coalescing to 0.
                    GDP = range[1]?.DoubleValue != null ? (decimal)range[1].DoubleValue : 0m
                };

                // Add the newly created Country entity to the Countries set asynchronously.
                await countryContext.Countries.AddAsync(country);
            }

            // Commit and save all changes made in this context to the database asynchronously.
            await countryContext.SaveChangesAsync();
        }
    }
    catch (Exception ex)
    {
        // Log or handle exceptions here.
        Console.WriteLine($"An error occurred: {ex.Message}");
    }
}

// Note: Definitions for `Country` entity and `CountryContext` DbContext would also be required
// for this code to be fully functional. Ensure the `CountryContext` class inherits from DbContext
// and that the Entities are properly configured.

Imports System.Threading.Tasks

Imports IronXL

Imports Microsoft.EntityFrameworkCore



' This method processes an Excel worksheet to extract country names and GDP values,

' then saves them into a database.

Public Async Function ProcessAsync() As Task

	Try

		' Load the workbook from the specified file path.

		Dim workbook = WorkBook.Load("Spreadsheets\GDP.xlsx")



		' Get the worksheet named "GDPByCountry" from the workbook.

		Dim worksheet = workbook.GetWorkSheet("GDPByCountry")



		' Create a database context for interacting with the Country database.

		Using countryContext As New CountryContext()

			' Iterate through each row of the worksheet from row 2 to 213.

			For i = 2 To 213

				' Fetch the range of cells from columns A to B in the current row.

				Dim range = worksheet($"A{i}:B{i}").ToList()



				' Ensure there are at least two cells in the range.

				If range.Count < 2 Then

					Continue For ' Skip rows that do not have both columns filled.

				End If



				' Create a Country entity object to be stored in the database.

				Dim country As New Country With {

					.Name = range(0)?.ToString()?.Trim(),

					.GDP = If(range(1)?.DoubleValue IsNot Nothing, CDec(range(1).DoubleValue), 0D)

				}



				' Add the newly created Country entity to the Countries set asynchronously.

				Await countryContext.Countries.AddAsync(country)

			Next i



			' Commit and save all changes made in this context to the database asynchronously.

			Await countryContext.SaveChangesAsync()

		End Using

	Catch ex As Exception

		' Log or handle exceptions here.

		Console.WriteLine($"An error occurred: {ex.Message}")

	End Try

End Function



' Note: Definitions for `Country` entity and `CountryContext` DbContext would also be required

' for this code to be fully functional. Ensure the `CountryContext` class inherits from DbContext

' and that the Entities are properly configured.

using System;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace CountryApp
{
    // Simulated Client class to demonstrate async HTTP requests.
    public class Client
    {
        private readonly Uri _baseUri;

        // Constructor to initialize the client with a base URI.
        public Client(Uri baseUri)
        {
            _baseUri = baseUri;
        }

        // Asynchronous method to perform a GET request and deserialize the response.
        // This is a placeholder for actual HTTP client code.
        public async Task<List<RestCountry>> GetAsync()
        {
            // Note: In a real application, you would replace the following line with HTTP request logic.
            // This demonstration assumes a mock response already available as List<RestCountry>.
            return await Task.FromResult(new List<RestCountry>
            {
                // Simulate some response data for demonstration
                new RestCountry { Name = "Country1" },
                new RestCountry { Name = "Country2" }
            });
        }
    }

    // Assume RestCountry is a class with properties matching the expected response data structure.
    // This class should be modified to match the expected JSON properties.
    public class RestCountry
    {
        // Example property for demonstration; customize based on actual API response.
        public string Name { get; set; }
    }

    class Program
    {
        // Main entry point demonstrating usage of the Client class with await functionality.
        static async Task Main(string[] args)
        {
            await RetrieveCountries();
        }

        // Asynchronous method to initiate HTTP request and process the response.
        static async Task RetrieveCountries()
        {
            // Initialize client with the base URL for the REST API.
            var client = new Client(new Uri("https://restcountries.com/v3.1/all"));

            // Asynchronously retrieve the list of countries.
            List<RestCountry> countries = await client.GetAsync();

            // Output the list of countries to demonstrate success.
            foreach (var country in countries)
            {
                Console.WriteLine(country.Name);
            }
        }
    }
}

Imports System

Imports System.Collections.Generic

Imports System.Threading.Tasks



Namespace CountryApp

	' Simulated Client class to demonstrate async HTTP requests.

	Public Class Client

		Private ReadOnly _baseUri As Uri



		' Constructor to initialize the client with a base URI.

		Public Sub New(ByVal baseUri As Uri)

			_baseUri = baseUri

		End Sub



		' Asynchronous method to perform a GET request and deserialize the response.

		' This is a placeholder for actual HTTP client code.

		Public Async Function GetAsync() As Task(Of List(Of RestCountry))

			' Note: In a real application, you would replace the following line with HTTP request logic.

			' This demonstration assumes a mock response already available as List<RestCountry>.

			Return Await Task.FromResult(New List(Of RestCountry) From {

				New RestCountry With {.Name = "Country1"},

				New RestCountry With {.Name = "Country2"}

			})

		End Function

	End Class



	' Assume RestCountry is a class with properties matching the expected response data structure.

	' This class should be modified to match the expected JSON properties.

	Public Class RestCountry

		' Example property for demonstration; customize based on actual API response.

		Public Property Name() As String

	End Class



	Friend Class Program

		' Main entry point demonstrating usage of the Client class with await functionality.

		Shared Async Function Main(ByVal args() As String) As Task

			Await RetrieveCountries()

		End Function



		' Asynchronous method to initiate HTTP request and process the response.

		Private Shared Async Function RetrieveCountries() As Task

			' Initialize client with the base URL for the REST API.

			Dim client As New Client(New Uri("https://restcountries.com/v3.1/all"))



			' Asynchronously retrieve the list of countries.

			Dim countries As List(Of RestCountry) = Await client.GetAsync()



			' Output the list of countries to demonstrate success.

			For Each country In countries

				Console.WriteLine(country.Name)

			Next country

		End Function

	End Class

End Namespace

// Assumes that the required libraries for working with this type of spreadsheet are imported.

// Assuming existence of a method GetColumnLetter(int index) that returns the corresponding Excel column letter.
// This method is not provided here but should map an integer index to a string representing the Excel column (e.g., 1 -> "A", 2 -> "B").

for (var i = 0; i < countries.Count; i++)
{
    var country = countries[i];
    
    // Set the basic values for each country's data in the specified columns.
    // i+1 is used to convert zero-based index to Excel row number.
    workSheet[$"A{i + 1}"].Value = country.name; 
    workSheet[$"B{i + 1}"].Value = country.population;
    workSheet[$"G{i + 1}"].Value = country.region;
    workSheet[$"H{i + 1}"].Value = country.numericCode;
    
    // Iterate through the first 3 languages or the number of available languages, whichever is smaller.
    for (var x = 0; x < 3; x++)
    {
        // Break out of the loop if there are no more languages to process.
        if (x >= country.languages.Count) break;

        var language = country.languages[x];
        
        // Get the letter representation for the column by computing the correct column shift.
        var columnLetter = GetColumnLetter(4 + x); // 4 is used to map to the starting language column ("D")

        // Set the language name in the appropriate cell.
        workSheet[$"{columnLetter}{i + 1}"].Value = language.name;
    }
}

' Assumes that the required libraries for working with this type of spreadsheet are imported.



' Assuming existence of a method GetColumnLetter(int index) that returns the corresponding Excel column letter.

' This method is not provided here but should map an integer index to a string representing the Excel column (e.g., 1 -> "A", 2 -> "B").



For i = 0 To countries.Count - 1

	Dim country = countries(i)



	' Set the basic values for each country's data in the specified columns.

	' i+1 is used to convert zero-based index to Excel row number.

	workSheet($"A{i + 1}").Value = country.name

	workSheet($"B{i + 1}").Value = country.population

	workSheet($"G{i + 1}").Value = country.region

	workSheet($"H{i + 1}").Value = country.numericCode



	' Iterate through the first 3 languages or the number of available languages, whichever is smaller.

	For x = 0 To 2

		' Break out of the loop if there are no more languages to process.

		If x >= country.languages.Count Then

			Exit For

		End If



		Dim language = country.languages(x)



		' Get the letter representation for the column by computing the correct column shift.

		Dim columnLetter = GetColumnLetter(4 + x) ' 4 is used to map to the starting language column ("D")



		' Set the language name in the appropriate cell.

		workSheet($"{columnLetter}{i + 1}").Value = language.name

	Next x

Next i