Gets or sets border line style.
Note that although diagonal-up (IndividualBorder.DiagonalUp or MultipleBorders.DiagonalUp) and diagonal-down (IndividualBorder.DiagonalDown or MultipleBorders.DiagonalDown) can be individually set, they share the same color and the same line style. This is a Microsoft Excel limitation.
CellBorder Class | GemBox.Spreadsheet Namespace