property Column.HeaderUnderline as Boolean

Retrieves or sets a value that indicates whether the column's caption should appear in underline.

TypeDescription
Boolean A boolean expression that indicates whether the column's caption should appear in underline.

Use the HeaderUnderline property to specify whether the column's caption should appear in underline. Use the CellUnderline or ItemUnderline properties to specify whether the cell or the item should appear in underline. 

For instance, the following samples show how to bold the entire column, by handling the AddItem event: 

Private Sub ExplorerTree1_AddItem(ByVal Group As EXPLORERTREELibCtl.IGroup, ByVal Item As EXPLORERTREELibCtl.HITEM)
    Group.Items.CellBold(Item, 0) = True
End Sub