Code

class ShapeNodeEx : ShapeNode
{
	StringFormat labelFormat = new StringFormat
	{
		LineAlignment = StringAlignment.Near,
		Alignment = StringAlignment.Center
	};

	public override void Draw(IGraphics graphics, RenderOptions options)
	{
		options.EnableText = false;
		base.Draw(graphics, options);
		options.EnableText = true;

		var textRect = GetRotatedBounds();
		textRect.Y += textRect.Height + 1;
		graphics.DrawString(
			Text, EffectiveFont, Brushes.Black,
			textRect, labelFormat);
	}

	public override RectangleF GetRepaintRect(bool includeConnected)
	{
		var repaintRect = base.GetRepaintRect(includeConnected);
		var textRect = GetRotatedBounds();
		textRect.Y += textRect.Height + 1;
		return RectangleF.Union(repaintRect, textRect);
	}
}