Reading CSV Files in C#: a Tutorial

What is CSV?

CSV is a simple data format, but there can be many differences; it can be difficult to read programmatically in our C# projects because it uses several delimiters for distinguishing between rows and columns of data. This article will show you how to use the IronXL library to read CSV files.

1. How to read a CSV File in C#

Before you can make use of IronXL to read CSV files in MVC, ASP.NET or .NET Core, you need to install it. Here is a quick walk-through.

1. In Visual Studio, select the Project menu
2. Manage NuGet Packages
3. Search for IronXL.Excel
4. Install

Search for IronXL in NuGet Package Manager in Visual Studio

When you need to read CSV files in C#, IronXL is the perfect tool. You can read a CSV file with commas, or any other delimiter, as seen in the code segments below.

// Load a CSV file and interpret it as an Excel-like workbook
WorkBook workbook = WorkBook.LoadCSV("Weather.csv", fileFormat: ExcelFileFormat.XLSX, ListDelimiter: ",");

// Access the default worksheet in the workbook
WorkSheet ws = workbook.DefaultWorkSheet;

// Save the workbook to a new Excel file
workbook.SaveAs("Csv_To_Excel.xlsx");

// Load a CSV file and interpret it as an Excel-like workbook
WorkBook workbook = WorkBook.LoadCSV("Weather.csv", fileFormat: ExcelFileFormat.XLSX, ListDelimiter: ",");

// Access the default worksheet in the workbook
WorkSheet ws = workbook.DefaultWorkSheet;

// Save the workbook to a new Excel file
workbook.SaveAs("Csv_To_Excel.xlsx");

Output:

Output CSV file with comma delimiter

Code Explanation:

A WorkBook object is created. The LoadCSV method for the WorkBook object is then used to specify the name of the CSV, its format, and which delimiters are used in the CSV file being read. In this case, commas are used as delimiters.

A WorkSheet object is then created. This is where the contents of the CSV file will be placed. The file is saved under a new name and format.

Data displayed in Microsoft Excel

2. IronXL for Excel Files

Use IronXL for your project as a streamlined way to work with Excel file formats in C#. You can either install IronXL via direct download. Alternatively, you can use NuGet Install for Visual Studio. The software is free for development.

dotnet add package IronXL.Excel

3. Load WorkBook and Access WorkSheet

WorkBook is the class of IronXL whose object provides full access to the Excel file and all of its functions. For example, if we want to access an Excel file, we'd use the code:

// Load the Excel file
WorkBook wb = WorkBook.Load("sample.xlsx"); // Excel file path

// Load the Excel file
WorkBook wb = WorkBook.Load("sample.xlsx"); // Excel file path

To access the specific worksheet of an Excel file, IronXL provides the WorkSheet class.

// Access a specific worksheet by name
WorkSheet ws = wb.GetWorkSheet("Sheet1"); // by sheet name

// Access a specific worksheet by name
WorkSheet ws = wb.GetWorkSheet("Sheet1"); // by sheet name

Once you have obtained the Excel worksheet ws, you can extract any type of data from it and perform all Excel functions on it. Data can be accessed from the Excel worksheet ws through this process:

using IronXL;

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Iterate through a range of cells and display their values
        foreach (var cell in ws["A2:A10"])
        {
            Console.WriteLine("Value is: {0}", cell.Text);
        }
        Console.ReadKey();
    }
}

using IronXL;

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Iterate through a range of cells and display their values
        foreach (var cell in ws["A2:A10"])
        {
            Console.WriteLine("Value is: {0}", cell.Text);
        }
        Console.ReadKey();
    }
}

4. Reading an Excel WorkSheet as a DataTable

Using IronXL, it is very easy to operate with an Excel WorkSheet as a DataTable.

DataTable dt = ws.ToDataTable(true); // Converts the worksheet to a DataTable, using the first row as column names

DataTable dt = ws.ToDataTable(true); // Converts the worksheet to a DataTable, using the first row as column names

Use the following namespaces:

using IronXL;
using System.Data;

using IronXL;
using System.Data;

Write the following code:

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("Weather.xlsx"); // Your Excel file Name
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse worksheet into datatable
        DataTable dt = ws.ToDataTable(true); // Parse Sheet1 of sample.xlsx file into DataTable

        // Iterate through rows and columns to display their values
        foreach (DataRow row in dt.Rows) // Access rows
        {
            for (int i = 0; i < dt.Columns.Count; i++) // Access columns of corresponding row
            {
                Console.Write(row[i] + "  ");
            }
            Console.WriteLine();
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("Weather.xlsx"); // Your Excel file Name
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse worksheet into datatable
        DataTable dt = ws.ToDataTable(true); // Parse Sheet1 of sample.xlsx file into DataTable

        // Iterate through rows and columns to display their values
        foreach (DataRow row in dt.Rows) // Access rows
        {
            for (int i = 0; i < dt.Columns.Count; i++) // Access columns of corresponding row
            {
                Console.Write(row[i] + "  ");
            }
            Console.WriteLine();
        }
    }
}

Console output from a DataTable object

In this example, we will look at how to use an Excel file as a DataSet.

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and convert it to a DataSet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        DataSet ds = wb.ToDataSet(); // Parse WorkBook wb into DataSet

        // Iterate through tables to display their names
        foreach (DataTable dt in ds.Tables)
        {
            Console.WriteLine(dt.TableName);
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and convert it to a DataSet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        DataSet ds = wb.ToDataSet(); // Parse WorkBook wb into DataSet

        // Iterate through tables to display their names
        foreach (DataTable dt in ds.Tables)
        {
            Console.WriteLine(dt.TableName);
        }
    }
}

Access sheet name from DataSet object

Let's look at another example of how to access each cell value across all Excel sheets. Here, we can access each cell value of every WorkSheet in an Excel file.

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and convert it to a DataSet
        WorkBook wb = WorkBook.Load("Weather.xlsx");
        DataSet ds = wb.ToDataSet(); // Treat the complete Excel file as DataSet

        // Iterate through each table and its rows and columns
        foreach (DataTable dt in ds.Tables) // Treat Excel WorkSheet as DataTable
        {
            foreach (DataRow row in dt.Rows) // Corresponding Sheet's Rows
            {
                for (int i = 0; i < dt.Columns.Count; i++) // Sheet columns of corresponding row
                {
                    Console.Write(row[i] + "  ");
                }
                Console.WriteLine();
            }
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and convert it to a DataSet
        WorkBook wb = WorkBook.Load("Weather.xlsx");
        DataSet ds = wb.ToDataSet(); // Treat the complete Excel file as DataSet

        // Iterate through each table and its rows and columns
        foreach (DataTable dt in ds.Tables) // Treat Excel WorkSheet as DataTable
        {
            foreach (DataRow row in dt.Rows) // Corresponding Sheet's Rows
            {
                for (int i = 0; i < dt.Columns.Count; i++) // Sheet columns of corresponding row
                {
                    Console.Write(row[i] + "  ");
                }
                Console.WriteLine();
            }
        }
    }
}

Console output of Dataset object

5. CSV parsing in C# .NET

CSV files have an abundance of issues with how line breaks are handled in fields, or how fields can be contained in quotes that completely block a simple string split approach. I have recently discovered the following options when converting CSV in C# .NET by specifying a customizable delimiter instead of using string.Split(',') to separate the values in a comma.

6. Reading CSV Data in C# Records

This process advances the reader through the next file. We read the CSV field files in TryGetField. We use the read function on field fields of the CSV files as record fields.

// Load a CSV file, specify the file format and delimiter
WorkBook workbook = WorkBook.LoadCSV("Weather.csv", fileFormat: ExcelFileFormat.XLSX, ListDelimiter: ",");

// Access the default worksheet from the workbook
WorkSheet ws = workbook.DefaultWorkSheet;

// Convert worksheet to DataTable    
DataTable dt = ws.ToDataTable(true); // Parse Sheet1 of sample.xlsx file into DataTable

// Iterate through rows and columns to display their values
foreach (DataRow row in dt.Rows) // Access rows
{
    for (int i = 0; i < dt.Columns.Count; i++) // Access columns of corresponding row
    {
        Console.Write(row[i] + "  ");
    }
    Console.WriteLine();
}

// Load a CSV file, specify the file format and delimiter
WorkBook workbook = WorkBook.LoadCSV("Weather.csv", fileFormat: ExcelFileFormat.XLSX, ListDelimiter: ",");

// Access the default worksheet from the workbook
WorkSheet ws = workbook.DefaultWorkSheet;

// Convert worksheet to DataTable    
DataTable dt = ws.ToDataTable(true); // Parse Sheet1 of sample.xlsx file into DataTable

// Iterate through rows and columns to display their values
foreach (DataRow row in dt.Rows) // Access rows
{
    for (int i = 0; i < dt.Columns.Count; i++) // Access columns of corresponding row
    {
        Console.Write(row[i] + "  ");
    }
    Console.WriteLine();
}

Console output from DataTable

7. Getting Data from Excel Files

Now we can easily get any type of data, using a variety of methods, from the open Excel WorkSheet. In the following example, we can see how to access a specific cell value and parse it to string:

// Access the data by cell addressing
string val = ws["Cell Address"].ToString();

// Access the data by cell addressing
string val = ws["Cell Address"].ToString();

In the line above, ws is the WorkSheet, which was defined in Step 2. This is 'the simple' approach, but you can read more and see different examples of how to access Excel file data.

8. How to Parse Excel Files in C#

When using Excel Spreadsheets for application builds, we often analyze the results based on data and need to parse Excel file data within C# into the required format to get the right results. Parsing data into different formats is made easy in the C# environment with the use of IronXL; see the steps below.

using IronXL;

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse Excel cell value into string
        string str_val = ws["B3"].Value.ToString();

        // Parse Excel cell value into Int32
        Int32 int32_val = ws["G3"].Int32Value;

        // Parse Excel cell value into Decimal
        decimal decimal_val = ws["E5"].DecimalValue;

        // Output parsed values to the console
        Console.WriteLine("Parse B3 Cell Value into String: {0}", str_val);
        Console.WriteLine("Parse G3 Cell Value into Int32: {0}", int32_val);
        Console.WriteLine("Parse E5 Cell Value into decimal: {0}", decimal_val);

        Console.ReadKey();
    }
}

using IronXL;

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse Excel cell value into string
        string str_val = ws["B3"].Value.ToString();

        // Parse Excel cell value into Int32
        Int32 int32_val = ws["G3"].Int32Value;

        // Parse Excel cell value into Decimal
        decimal decimal_val = ws["E5"].DecimalValue;

        // Output parsed values to the console
        Console.WriteLine("Parse B3 Cell Value into String: {0}", str_val);
        Console.WriteLine("Parse G3 Cell Value into Int32: {0}", int32_val);
        Console.WriteLine("Parse E5 Cell Value into decimal: {0}", decimal_val);

        Console.ReadKey();
    }
}

9. How to Parse Excel Data Into Numeric & Boolean Values

Now we move to how to parse Excel file data. First, we look at how to deal with numeric Excel data, and then how to parse it into our required format.

Summary table for each data type

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse Excel cell value into string
        string str_val = ws["B3"].Value.ToString();

        // Parse Excel cell value into Int32
        Int32 int32_val = ws["G3"].Int32Value;

        // Parse Excel cell value into Decimal
        decimal decimal_val = ws["E5"].DecimalValue;

        // Output parsed values to the console
        Console.WriteLine("Parse B3 Cell Value into String: {0}", str_val);
        Console.WriteLine("Parse G3 Cell Value into Int32: {0}", int32_val);
        Console.WriteLine("Parse E5 Cell Value into decimal: {0}", decimal_val);

        Console.ReadKey();
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse Excel cell value into string
        string str_val = ws["B3"].Value.ToString();

        // Parse Excel cell value into Int32
        Int32 int32_val = ws["G3"].Int32Value;

        // Parse Excel cell value into Decimal
        decimal decimal_val = ws["E5"].DecimalValue;

        // Output parsed values to the console
        Console.WriteLine("Parse B3 Cell Value into String: {0}", str_val);
        Console.WriteLine("Parse G3 Cell Value into Int32: {0}", int32_val);
        Console.WriteLine("Parse E5 Cell Value into decimal: {0}", decimal_val);

        Console.ReadKey();
    }
}

This code will display the following output:

Console output with correct data type

And we can see the values of the Excel file sample.xlsx here:

Display correct data type in Excel

To parse Excel file data into Boolean data type, IronXL provides the BoolValue function. It can be used as follows:

// Access a cell value as a boolean
bool Val = ws["Cell Address"].BoolValue;

// Access a cell value as a boolean
bool Val = ws["Cell Address"].BoolValue;

10. How to Parse Excel Files into C# Collections

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Convert a range into an array
        var array = ws["B6:F6"].ToArray();

        // Get the count of items in the array
        int item = array.Count();

        // Get the first item as a string
        string total_items = array[0].Value.ToString();

        // Output information about the array to the console
        Console.WriteLine("First item in the array: {0}", item);
        Console.WriteLine("Total items from B6 to F6: {0}", total_items);

        Console.ReadKey();
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Convert a range into an array
        var array = ws["B6:F6"].ToArray();

        // Get the count of items in the array
        int item = array.Count();

        // Get the first item as a string
        string total_items = array[0].Value.ToString();

        // Output information about the array to the console
        Console.WriteLine("First item in the array: {0}", item);
        Console.WriteLine("Total items from B6 to F6: {0}", total_items);

        Console.ReadKey();
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse Sheet1 of sample.xlsx file into DataTable
        // Setting 'true' makes the first row in Excel as the column names in DataTable
        DataTable dt = ws.ToDataTable(true);
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Parse Sheet1 of sample.xlsx file into DataTable
        // Setting 'true' makes the first row in Excel as the column names in DataTable
        DataTable dt = ws.ToDataTable(true);
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load an entire workbook into a DataSet
        WorkBook wb = WorkBook.Load("sample.xlsx");

        // Convert workbook to DataSet
        DataSet ds = wb.ToDataSet();

        // We can also get a DataTable from the DataSet which corresponds to a WorkSheet
        DataTable dt = ds.Tables[0];
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load an entire workbook into a DataSet
        WorkBook wb = WorkBook.Load("sample.xlsx");

        // Convert workbook to DataSet
        DataSet ds = wb.ToDataSet();

        // We can also get a DataTable from the DataSet which corresponds to a WorkSheet
        DataTable dt = ds.Tables[0];
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Get specified range values by loop
        foreach (var item in ws["B3:B8"])
        {
            Console.WriteLine("Value is: {0}", item);
        }
        Console.ReadKey();
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Get specified range values by loop
        foreach (var item in ws["B3:B8"])
        {
            Console.WriteLine("Value is: {0}", item);
        }
        Console.ReadKey();
    }
}

11. How to Read Boolean Data in an Excel File

In application development, we need to make decisions based on the Boolean data type in Excel files.

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Traverse a range and output boolean values
        foreach (var item in ws["G1:G10"])
        {
            Console.WriteLine("Condition is: {0}", item.BoolValue);
        }
        Console.ReadKey();
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("sample.xlsx");
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Traverse a range and output boolean values
        foreach (var item in ws["G1:G10"])
        {
            Console.WriteLine("Condition is: {0}", item.BoolValue);
        }
        Console.ReadKey();
    }
}

From this, we get the output:

Console output from getting Boolean Data

And the Excel file sample.xlsx with values from C1 to C10:

Excel sample to compare with Console output

12. How to Read a Complete Excel WorkSheet

It is simple to read a complete Excel WorkSheet by using rows and columns indexes. For this purpose, we use two loops: one for traversing all rows, and the second for traversing all columns of a specific row. Then we can easily obtain all the cell values within the entire Excel WorkSheet.

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("Weather.xlsx"); // Your Excel File Name
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Traverse all rows of Excel WorkSheet
        for (int i = 0; i < ws.Rows.Count(); i++)
        {
            // Traverse all columns of specific Row
            for (int j = 0; j < ws.Columns.Count(); j++)
            {
                // Get the values
                string val = ws.Rows[i].Columns[j].Value.ToString();
                Console.WriteLine("Value of Row {0} and Column {1} is: {2}", i, j, val);
            }
        }
        Console.ReadKey();
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load the workbook and access a specific worksheet
        WorkBook wb = WorkBook.Load("Weather.xlsx"); // Your Excel File Name
        WorkSheet ws = wb.GetWorkSheet("Sheet1");

        // Traverse all rows of Excel WorkSheet
        for (int i = 0; i < ws.Rows.Count(); i++)
        {
            // Traverse all columns of specific Row
            for (int j = 0; j < ws.Columns.Count(); j++)
            {
                // Get the values
                string val = ws.Rows[i].Columns[j].Value.ToString();
                Console.WriteLine("Value of Row {0} and Column {1} is: {2}", i, j, val);
            }
        }
        Console.ReadKey();
    }
}

Console output from reading all values

13. How to Read Excel Files without Interop

IronXL is an Excel Library for C# and .NET which allows developers to read and edit Excel data from XLS and XLSX Documents without using Microsoft.Office.Interop.Excel.

The API allows us to create, read, manipulate, save and export Excel files intuitively for:

1. .NET Framework 4.5+
2. .NET Core 2+
3. .NET Standard
4. Xamarin
5. Windows Mobile
6. Mono
7. & Azure Cloud Hosting
8. Blazor
9. .NET MAUI

Add the following namespaces:

using IronXL;
using System;
using System.Linq;

using IronXL;
using System;
using System.Linq;

Now write the following code inside the main function.

class Program
{
    static void Main(string[] args)
    {
        // Load an Excel file and access the first worksheet
        WorkBook workbook = WorkBook.Load("Weather.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);
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Load an Excel file and access the first worksheet
        WorkBook workbook = WorkBook.Load("Weather.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);
        }
    }
}

Console output from each cell

IronXL also fully supports ASP.NET, MVC, Windows, macOS, Linux, iOS, and Android Mobile application development.

14. Conclusion and Iron XL Special Offer

In addition to CSV parsing in C#, IronXL converts CSV files to Excel with just two lines of code!

Using C# or VB.NET, it is very easy to use IronXL's Excel API without the need for Interop. You can read, edit, and create Excel spreadsheets or work with other Excel formats such as XLS/XLSX/CSV/TSV. With the support of multiple frameworks, you can buy 5 products for the price of two. Click on our pricing page for further information.

5 products of Iron Suite