winform 旋转图片

            //img.RotateFlip(RotateFlipType.Rotate90FlipNone);
            //顺时针旋转90度 RotateFlipType.Rotate90FlipNone
            //逆时针旋转90度 RotateFlipType.Rotate270FlipNone
            //水平翻转 RotateFlipType.Rotate180FlipY
            //垂直翻转 RotateFlipType.Rotate180FlipX

            Image img = pictureBox1.Image;
            img.RotateFlip(RotateFlipType.Rotate90FlipNone);
            pictureBox1.Image = img;