ExcelWriter creates three style types: GlobalStyle, NamedStyle, and CellStyle. All three style types derive from the Style class, and NamedStyle derives from GlobalStyle.

 public sealed class NamedStyle : GlobalStyle
Public NotInheritable Class NamedStyle
		Inherits GlobalStyle

A style can be set or applied to cells, rows, columns, ranges, and areas. When a style is set , it is cloned and the object to which the style is assigned acquires all of that style's properties, including font proprties and number formatting. When a style is applied , only the differences between the new style and existing style properties (assigned through the ExcelWriter API or in Microsoft Excel) will take effect. For example, if the cell has a background color and the new style applied does not contain a background color, the cell's color will not be affected. However, if the new style includes a background color, it will replace the existing background color of the cell.

The ExcelApplication object contains a collection of NamedStyle s, which - unlike GlobalStyle s are accessible after the workbook is saved. This allows you to dynamically create a template, save it to disk, re-open it to populate it with data, and then apply your newly-created style. This collection of NamedStyle s includes Excel's built-in styles (such as the NORMAL style) and any user-defined styles in a workbook opened with the ExcelApplication object.

To create a NamedStyle, call Workbook.CreateNamedStyle.

To return a NamedStyle, call Workbook.GetNamedStyle.

          ExcelApplication xla = new ExcelApplication();
          Workbook wb = xla.Create();

          //--- Create a named style.
          Style myItalicStyle = wb.CreateNamedStyle("ItalicStyle");

          //--- Turn on italics for the named style.
          myGlobalStyle.Font.Italics = true;

          //--- Get a "total" cell
          Cell totalCell = wb.Worksheets[0].Cells[4, 4];

          //--- Check its value and apply style if necessary
          if(totalCell.Value > TARGET_TOTAL_VALUE)

          Dim xla As New ExcelApplication()
          Workbook wb = xla.Create()

          '--- Create a named style.
          Dim myItalicStyle As Style = wb.CreateNamedStyle("ItalicStyle")

          '--- Turn on italics for the named style
          myGlobalStyle.Font.Italics = True

          '--- Get a "total" cell
          Dim totalCall As Cell = wb.Worksheets(0).Cells(4, 4)

          '--- Check its value and apply style if necessary
          If totalCell.Value > TARGET_TOTAL_VALUE Then
          End If