Read Excel in C# with Simple Code

Source: Dev.to

Introduction

In daily C# development, processing Excel data is a requirement almost every developer encounters. Whether it’s importing user data, generating reports, or conducting data analysis, Excel plays an indispensable role. Traditional C# Excel reading methods—such as Microsoft.Office.Interop.Excel based on COM Interop—are often plagued by performance bottlenecks, environment dependencies, and complex deployment.

This article shows how to implement a simple, efficient Excel reading solution using Spire.XLS for .NET, with no Office dependencies required.

Environment Preparation

Step 1: Create a VS2022 Console Project

• File → New → Project → Console App template.

Step 2: Install via NuGet

• Graphic Interface: Right‑click the project → Manage NuGet Packages → Search for FreeSpire.XLS.

• Command Line:

  Install-Package Spire.XLS
  # or the free version
  Install-Package FreeSpire.XLS

Verify the installation by confirming that the Spire.XLS assembly appears in the project references.

Read Excel Files in C# Quickly

Import the Namespace

using Spire.Xls;

Read Individual Cells

// Load Excel (supports both XLS and XLSX formats)
Workbook wb = new Workbook();
wb.LoadFromFile("Sample.xlsx");

// Read cell data (2 methods)
Worksheet sheet = wb.Worksheets[0];
Console.WriteLine(sheet.Range["A1"].Value);      // Locate by column name
Console.WriteLine(sheet.Range[2, 1].Value);      // Locate by row and column numbers

Common Pitfall: When reading data by row and column numbers, the indexes start from 1, not 0.

Read Data from an Entire Worksheet

using Spire.Xls;

namespace ReadExcelData
{
    class Program
    {
        static void Main(string[] args)
        {
            // Load the Excel document
            Workbook wb = new Workbook();
            wb.LoadFromFile("Sample.xlsx");

            // Get the first worksheet
            Worksheet sheet = wb.Worksheets[0];

            // Get the data range in the worksheet
            CellRange locatedRange = sheet.AllocatedRange;

            // Iterate through rows and columns in the range
            for (int i = 0; i < locatedRange.Rows.Length; i++)
            {
                for (int j = 0; j < locatedRange.Rows[i].ColumnCount; j++)
                {
                    // Read cell data
                    Console.Write(locatedRange[i + 1, j + 1].Value + "  ");
                }
                Console.WriteLine();
            }
        }
    }
}

Read Excel Formulas

The Value property returns the formula itself. To obtain the calculated result, use FormulaValue.

foreach (CellRange cell in sheet.AllocatedRange)
{
    if (cell.HasFormula)
    {
        // Original formula
        string formula = cell.Formula;

        // Calculated result of the formula
        string formulaResult = cell.FormulaValue.ToString();
    }
}

Reading Excel files in C# is a common task. Choosing the right tool—such as Spire.XLS—can greatly improve development efficiency and program stability.