FarPoint.Win.Spread.FpSpread fpSpread1 = new FarPoint.Win.Spread.FpSpread();
FarPoint.Win.Spread.SheetView shv = new FarPoint.Win.Spread.SheetView();
DialogResult dlg;
fpSpread1.Location = new Point(10, 10);
fpSpread1.Height = 200;
fpSpread1.Width = 400;
Controls.Add(fpSpread1);
fpSpread1.Sheets.Add(shv);
fpSpread1.AddViewport(0, 0);
dlg = MessageBox.Show("Do you want to remove the viewport??", "RemoveViewport", MessageBoxButtons.YesNo);
if (dlg == DialogResult.Yes)
{
fpSpread1.RemoveViewport(0,0);
}