图片缩放/旋转/平移/设置分辨率

#region 设置分辨率
            using (Graphics g = pictureBox2.CreateGraphics())
            {
                g.Clear(pictureBox2.BackColor);//清空
                Bitmap bmp = new Bitmap(pictureBox1.Image);//创建bitmap对象
                ///设置分辨率
                bmp.SetResolution(500F, 500F);
                //重绘图像
                g.DrawImage(bmp, pictureBox2.ClientRectangle, 0, 0, bmp.Width, bmp.Height, GraphicsUnit.Pixel);
                bmp.Dispose();
            }
            #endregion

#region 缩放
            using (Graphics g = pictureBox2.CreateGraphics())
            {
                g.Clear(pictureBox2.BackColor);//清空
                using (Image image = Image.FromFile("3.jpg"))
                {
                    g.ScaleTransform(0.5F, 0.5F, System.Drawing.Drawing2D.MatrixOrder.Append);
                    int width = Convert.ToInt32(0.5 * image.Width);//缩放宽度
                    int height = Convert.ToInt32(0.5 * image.Height);//缩放高度
                    g.DrawImage(image, this.ClientSize.Width / 2, this.ClientSize.Height / 2, width, height);//绘制图像
                }
            }
            #endregion

 #region 平移
            Image img = pictureBox1.Image = Image.FromFile("3.jpg"); 
            using (Graphics g = pictureBox2.CreateGraphics())
            {
                g.Clear(pictureBox2.BackColor);//清空 
                ///平移 
                g.TranslateTransform(0F, 200F);
                //重绘图像 
                g.DrawImage(img, this.pictureBox1.ClientRectangle, 0, 0, img.Width, img.Height, GraphicsUnit.Pixel);
            }
            #endregion

            Image img = pictureBox1.Image = Image.FromFile("4.bmp");

 img.RotateFlip(RotateFlipType.RotateNoneFlipXY);//旋转

#region 旋转 绕顶点using (Graphics g = pictureBox2.CreateGraphics())
             {
                 g.Clear(pictureBox2.BackColor);//清空 
                 //旋转 
                 g.RotateTransform(20F);//旋转
                 //重绘图像 
                 g.DrawImage(img, this.pictureBox1.ClientRectangle, 0, 0, img.Width, img.Height, GraphicsUnit.Pixel);
             }
            #endregion


            #region 绕图片中心点旋转
            using (Graphics g = pictureBox2.CreateGraphics())//创建画板
            {
                //获取picturebox2的中心点
                Rectangle pRec = this.pictureBox2.ClientRectangle;
                PointF pCenter = new PointF(pRec.Width / 2, pRec.Height / 2);
                ///图片置picturebox2的中心点的偏移量
                float offsetX = pCenter.X - (img.Width / 2);
                float offsetY = pCenter.Y - (img.Height / 2);
                //图片旋转区域 其的中心点与picturebox2的中心点一致
                RectangleF newpRect = new RectangleF(offsetX, offsetY, img.Width, img.Height);
                ///旋转点
                PointF Pcenter = new PointF(pCenter.X, pCenter.Y);// new PointF(newpRect.X + newpRect.Width / 2, newpRect.Y + newpRect.Height / 2);
                //实现旋转 
                for (float i = 0; i < 36; i++)
                {
                    g.Clear(pictureBox2.BackColor);
                    //旋转角度
                    g.TranslateTransform(Pcenter.X, Pcenter.Y);
                    g.RotateTransform(10F);
                    g.TranslateTransform(-Pcenter.X, -Pcenter.Y);
                    //显示图像到中心
                    g.DrawImage(img, newpRect);// new PointF(pRec.Width / 4, pRec.Height / 4));
                    Thread.Sleep(20);
                }
            }
            #endregion