This C# example demonstrates how to select a specific range within an Excel worksheet and set the same value to all cells within that range using the FileFormat.Cells library.

set-range-value-in-worksheet.cs

using FileFormat.Cells;
// Load the workbook from the specified file path
using (Workbook wb = new Workbook(filePath))
{
    // Access the first worksheet in the workbook
    Worksheet firstSheet = wb.Worksheets[0];

    // Select a range within the worksheet
    var range = firstSheet.GetRange("A1", "B10");
    Console.WriteLine($"Column count: {range.ColumnCount}");
    Console.WriteLine($"Row count: {range.RowCount}");

    // Set a similar value to all cells in the selected range
    range.SetValue("Hello");

    // Save the changes back to the workbook
    wb.Save(filePath);

    Console.WriteLine("Value set to range and workbook saved successfully.");
}