public static extern GpStatus GdipDrawString( GpGraphics graphics, string text, INT length, GpFont font, ref RectF layoutRect, GpStringFormat stringFormat, GpBrush brush );
public static extern GpStatus GdipDeleteFont(GpFont font);
public static extern GpStatus GdipCreateFont(GpFontFamily fontFamily, float emSize, FontStyle style, Unit unit, out GpFont font);