TShapeProperties.ShapeLine Property
Line of the shape, for xlsx shapes (even those which are saved in xls files). This property has a more complete description of the line style than the one you can get by querying ShapeOptions, but will be null for xls files saved by Excel 2003 or earlier.
Syntax
Namespace: FlexCel.Core
public TShapeLine ShapeLine { get; set; }