merge 2

using OfficeOpenXml;

using OfficeOpenXml.Style;

using System;

using System.IO;

class Program

{

    static void Main()

    {

        // Required by EPPlus

        ExcelPackage.LicenseContext = LicenseContext.NonCommercial;

        string filePath = @"C:\Temp\input.xlsx";   // Input file

        string outputPath = @"C:\Temp\output.xlsx"; // Output file

        string sheetName = "Config"; // Target sheet

        using (var package = new ExcelPackage(new FileInfo(filePath)))

        {

            var worksheet = package.Workbook.Worksheets[sheetName];

            if (worksheet == null)

            {

                Console.WriteLine($"Sheet {sheetName} not found!");

                return;

            }

            int startRow = worksheet.Dimension.Start.Row + 1; // skip header row

            int endRow = worksheet.Dimension.End.Row;

            // Columns B, C, D → Excel is 1-based (B=2, C=3, D=4)

            int[] colsToCheck = { 2, 3, 4 };

            foreach (int col in colsToCheck)

            {

                int mergeStart = startRow;

                string prevValue = worksheet.Cells[startRow, col].Text;

                for (int row = startRow + 1; row <= endRow; row++)

                {

                    string currentValue = worksheet.Cells[row, col].Text;

                    // If values are different, OR previous value was empty → stop merge

                    if (currentValue != prevValue || string.IsNullOrWhiteSpace(prevValue))

                    {

                        if (row - 1 > mergeStart && !string.IsNullOrWhiteSpace(prevValue))

                        {

                            // Merge block

                            worksheet.Cells[mergeStart, col, row - 1, col].Merge = true;

                            worksheet.Cells[mergeStart, col, row - 1, col].Style.VerticalAlignment = ExcelVerticalAlignment.Center;

                            worksheet.Cells[mergeStart, col, row - 1, col].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;

                        }

                        mergeStart = row;

                        prevValue = currentValue;

                    }

                }

                // Handle last block (if not empty)

                if (endRow > mergeStart && !string.IsNullOrWhiteSpace(prevValue))

                {

                    worksheet.Cells[mergeStart, col, endRow, col].Merge = true;

                    worksheet.Cells[mergeStart, col, endRow, col].Style.VerticalAlignment = ExcelVerticalAlignment.Center;

                    worksheet.Cells[mergeStart, col, endRow, col].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;

                }

            }

            package.SaveAs(new FileInfo(outputPath));

            Console.WriteLine("Excel file processed and saved successfully!");

        }

    }

}