//字体旋转
Graphics g = e.Graphics;
g.TranslateTransform(20f, 10f);
g.RotateTransform(90); //<---
g.DrawString("横着呢", SystemFonts.DefaultFont, Brushes.Black, 0.0f, 0.0f);
g.ResetTransform();
// StringFormat f = new StringFormat(StringFormatFlags.DirectionVertical);
// g.DrawString("竖着的", SystemFonts.DefaultFont, Brushes.Blue, 100, 50, f);
g.TranslateTransform(60f, 10f);
g.RotateTransform(90);
g.DrawString("竖着的", SystemFonts.DefaultFont, Brushes.Blue, 60, 10);