How to rotate an image of picturebox with desired angle in C#?

 private void btnRotate_Click(object sender, EventArgs e)
        {
            Bitmap resultPicture = MoveImageByDesiredAngle(pictureBox1.Image.Width, pictureBox1.Image.Height, Convert.ToInt32(textBox1.Text));
            pictureBox1.Image = resultPicture;
        }

        private Bitmap MoveImageByDesiredAngle(int original_width , int original_height, int desiredAngle)
        {
            Bitmap resultPicture = new Bitmap(original_width, original_height);
            Graphics g = Graphics.FromImage(resultPicture);
            g.TranslateTransform((float)original_width / 2, (float)original_height / 2);
            g.RotateTransform(desiredAngle);
            g.TranslateTransform(-(float)original_width / 2, -(float)original_height / 2);           
            g.DrawImage(pictureBox1.Image , new Point(0, 0));
            return resultPicture;
        }