using System;

using System.Drawing;

using System.Drawing.Drawing2D;

​

namespace RotatePictureBox

{

    /// <summary>

    /// Summary description for Utilities.

    /// </summary>

    public sealed class Utilities

    {

        private Utilities()

        {

        }

        /// <summary>

        /// Creates a new Image containing the same image only rotated

        /// </summary>

        /// <param name="image">The <see cref="System.Drawing.Image"/> to rotate</param>

        /// <param name="angle">The amount to rotate the image, clockwise, in degrees</param>

        /// <returns>A new <see cref="System.Drawing.Bitmap"/> of the same size rotated.</returns>

        /// <exception cref="System.ArgumentNullException">Thrown if <see cref="image"/> is null.</exception>

        public static Bitmap RotateImage(Image image, float angle)

        {

            return RotateImage(image, new PointF((float)image.Width / 2, (float)image.Height / 2), angle);

        }

​

        /// <summary>

        /// Creates a new Image containing the same image only rotated

        /// </summary>

        /// <param name="image">The <see cref="System.Drawing.Image"/> to rotate</param>

        /// <param name="offset">The position to rotate from.</param>

        /// <param name="angle">The amount to rotate the image, clockwise, in degrees</param>

        /// <returns>A new <see cref="System.Drawing.Bitmap"/> of the same size rotated.</returns>

        /// <exception cref="System.ArgumentNullException">Thrown if <see cref="image"/> is null.</exception>

        public static Bitmap RotateImage(Image image, PointF offset, float angle)

        {

            if (image == null)

                throw new ArgumentNullException("image");

​

            //create a new empty bitmap to hold rotated image

            Bitmap rotatedBmp = new Bitmap(image.Width, image.Height);

            rotatedBmp.SetResolution(image.HorizontalResolution, image.VerticalResolution);

​

            //make a graphics object from the empty bitmap

            Graphics g = Graphics.FromImage(rotatedBmp);

​

            //Put the rotation point in the center of the image

            g.TranslateTransform(offset.X, offset.Y);

​

            //rotate the image

            g.RotateTransform(angle);

​

            //move the image back

            g.TranslateTransform(-offset.X, -offset.Y);

​

            //draw passed in image onto graphics object

            g.DrawImage(image, new PointF(0, 0));

​

            return rotatedBmp;

        }

    }

}