Styles and Formatting

dotnet-poi supports fonts, fills, borders, number formats, and alignment. All styles round-trip correctly.

Creating and Applying a Style

using DotnetPoi.XSSF.UserModel;
using DotnetPoi.SS.UserModel;

using var wb = new XSSFWorkbook();

var style = wb.createCellStyle();
var font = wb.createFont();

font.setBold(true);
font.setFontHeightInPoints(14);
font.setFontName("Arial");
font.setColor(IndexedColors.DarkBlue.Index);

style.setFont(font);
style.setAlignment(HorizontalAlignment.Center);

var sheet = wb.createSheet("Styled");
var row = sheet.createRow(0);
var cell = row.createCell(0);
cell.setCellValue("Styled cell");
cell.setCellStyle(style);

Font Properties

Method	Effect
`setBold(bool)`	Bold text
`setItalic(bool)`	Italic text
`setUnderline(byte)`	Underline style
`setStrikeout(bool)`	Strikethrough
`setFontName(string)`	Font family (e.g. "Arial", "Times New Roman")
`setFontHeightInPoints(int)`	Font size in points
`setColor(short)`	Text color (IndexedColors or custom)

Cell Fills

var style = wb.createCellStyle();
style.setFillForegroundColor(IndexedColors.LightYellow.Index);
style.setFillPattern(FillPatternType.SolidForeground);

Borders

style.setBorderBottom(BorderStyle.Thin);
style.setBorderTop(BorderStyle.Medium);
style.setBorderLeft(BorderStyle.Thin);
style.setBorderRight(BorderStyle.Thin);
style.setBottomBorderColor(IndexedColors.DarkBlue.Index);

Available border styles: None, Thin, Medium, Thick, Dashed, Dotted, Double, and more.

Number Formats

// Built-in formats
style.setDataFormat((short)0);  // General

// Custom format string
style.setDataFormat(wb.createDataFormat().getFormat("#,##0.00"));
style.setDataFormat(wb.createDataFormat().getFormat("yyyy-MM-dd"));
style.setDataFormat(wb.createDataFormat().getFormat("0.0%"));

Alignment

style.setAlignment(HorizontalAlignment.Center);       // horizontal
style.setVerticalAlignment(VerticalAlignment.Center); // vertical
style.setWrapText(true);                               // word wrap
style.setIndention(2);                                 // left indent (characters)
style.setRotation(45);                                 // text rotation (degrees)

Full Runnable Example

See examples/UsageSamples/Program.cs (CreateSpreadsheet):

examples/UsageSamples