This property is available at run time only.
Dim r As FarPoint.Win.Spread.RowHeader r = FpSpread1.ActiveSheet.RowHeader ListBox1.Items.Add(r.Rows.Count.ToString())
FarPoint.Win.Spread.RowHeader r; r = fpSpread1.ActiveSheet.RowHeader; listBox1.Items.Add(r.Rows.Count.ToString());