IShapeProperties.TextRotation Property
Text rotation: 0 means horizontal, 1 means vertical text, 2 means rotated -90 degrees clockwise, 3 means rotated 90 degrees clockwise. This method uses the xls way to set text rotation.
For more information, see Text Rotation In Xls And Xlsx
Syntax
Unit: FlexCel.Core
property IShapeProperties.TextRotation: Integer