NPOI-Styling merged cell

Question

I want to chenge ForegroundColor and set text in center at merged cell.

Is it possible to do that by NPOI?

This is my table:

I know how to set border.But I cant find resources about change merged cell style.

Can someone please give me some tips or help ?

Answer 1

For Row you'll have to set individually like this

XSSFSheet sheet = (XSSFSheet)workbook.CreateSheet("Template");
XSSFCellStyle headerStyle = (XSSFCellStyle)workbook.CreateCellStyle();
headerStyle.WrapText = true;
headerStyle.FillForegroundColor = IndexedColors.LightBlue.Index;
headerStyle.Alignment = HorizontalAlignment.Center;
var row = sheet.CreateRow(0);
row.Cells[YourheaderIndex].CellStyle = headerStyle;

For columns you can set the style like

XSSFCellStyle defaultStyle = (XSSFCellStyle)workbook.CreateCellStyle();
defaultStyle.WrapText = true;
defaultStyle.Alignment = HorizontalAlignment.Left;
defaultStyle.VerticalAlignment = VerticalAlignment.Top;
sheet.SetDefaultColumnStyle(YourheaderIndex, defaultStyle);

To apply style to merged cell you can try this approach , code is untested though but it will give good idea for available methods in NPOI

int mergedRegions = sheet.NumMergedRegions;
for (int regions = 0; regions < mergedRegions; regions++)
{
    CellRangeAddress mergedRegionIndex = sheet.GetMergedRegion(regions);

    for (int currentRegion = mergedRegionIndex.FirstRow; currentRegion < mergedRegionIndex.LastRow; currentRegion++)
    {
        var currentRow = sheet.GetRow(currentRegion);

        for (int currentCell = mergedRegionIndex.FirstColumn; currentCell < mergedRegionIndex.LastColumn; currentCell++)
        {
            // sheet.SetDefaultColumnStyle(i, mandatoryCellStyle);
            currentRow.Cells[currentCell].CellStyle = headerStyle;
        }
    }
}