private void Separator_Paint(object sender, PaintEventArgs e) { if (orientation == Orientation.Horizontal) { e.Graphics.DrawLine(BackColor.ToPen(), 0, 0, this.Width, 0); e.Graphics.DrawLine(ForeColor.ToPen(), 0, 1, this.Width, 1); } else if (orientation == Orientation.Vertical) { e.Graphics.DrawLine(BackColor.ToPen(), 0, 0, 0, this.Height); e.Graphics.DrawLine(ForeColor.ToPen(), 1, 0, 1, this.Height); } else { throw new NotImplementedException(); } }