property Tree.HeaderSingleLine as Boolean
Specifies whether the control resizes the columns header and wraps the captions in single or multiple lines.

TypeDescription
Boolean A boolean expression that specifies whether the header displays single or multiple lines.
By defauly, the HeaderSingleLine property is True. If the HeaderSingleLine property is False the control breaks the column's caption as soon as the user resizes the column. In this case the HeaderHeight property specifies the maximum height of the control's header. The initial height is computed based on the control's Font property. The Caption property specifies the caption of the column being displayed in the control's header. The HTMLCaption property specifies the HTML caption of the column being displayed in the column's header. Use the LevelKey property to display the control's header on multiple levels.

The following screen show shows the control's header while it displays a multiple lines ( HeaderSingleLine = False ):

The following screen shot shows the control's header on multiple levels using the LevelKey property:

The following screen show shows the control's header while it displays a single line ( HeaderSingleLine = True ):