C# GDI+封装

 public class CustomGDI
    {
        /// <summary>
        /// 图片宽
        /// </summary>
        public int Width { get; set; }
        /// <summary>
        /// 图片高
        /// </summary>
        public int Height { get; set; }
        private IntPtr _pointer { get; set; }

        /// <summary>
        /// 构造函数
        /// </summary>
        public CustomGDI()
        {

        }

        /// <summary>
        /// 设置图片大小
        /// </summary>
        /// <param name="width">图片宽</param>
        /// <param name="height">图片高</param>
        public void SetImagePtr(int width, int height)
        {
            Width = width;
            Height = height;
        }

        /// <summary>
        /// 画图
        /// </summary>
        /// <param name="graphicContext"></param>
        /// <param name="action">委托，添加文本、图像等</param>
        /// <param name="zoomX">显示比例</param>
        /// <param name="zoomY">显示比例</param>
        /// <param name="panX">显示位置</param>
        /// <param name="panY">显示位置</param>
        public void Draw(Graphics graphicContext, Action<Graphics> action, float zoomX, float zoomY, int panX, int panY)
        {
            lock(this)
            {
                int w_x = (int)(this.Width * zoomX);
                int h_y = (int)(this.Height * zoomY);
                var rect = new Rectangle(panX, panY, w_x, h_y);
                
                using (BufferedGraphicsContext currentContext = BufferedGraphicsManager.Current)
                {
                    using (BufferedGraphics myBuffer = currentContext.Allocate(graphicContext, rect))
                    {
                        using (Graphics g = myBuffer.Graphics)
                        {
                            if (action != null)
                                action(g);

                            // 如果某个缓冲区已被分配但尚未释放，则释放当前的图形缓冲区。
                            currentContext.Invalidate();
                            // 呈现图像至关联的Graphics
                            myBuffer.Render(graphicContext);
                        }
                    }
                }
            }
        }
    }

使用例子：

 Bitmap bm = new Bitmap(customGDI.Width, customGDI.Height);
using (Graphics g = Graphics.FromImage(bm))
{
    int x = 0, y = 0, i;
    customGDI.Draw(g, (Graphics gg) =>
    {
        Pen p = new Pen(Color.Red);
        Brush b = new SolidBrush(Color.Red);
        int t = random.Next(0, 4);
        for (i = 0; i < 4; i++)
        {
            a = a + i * 90 * Math.PI / 180;
            x = 320 + (int)(302.5 * Math.Cos(a));
            y = 320 + (int)(302.5 * Math.Sin(a));
            if (!indexs.Any(t => t == i))
                continue;

            Rectangle rect = new Rectangle(x, y, 15, 15);
            gg.DrawEllipse(p, rect);
            gg.FillEllipse(b, rect);
            gg.DrawString($"序号{i + 1}", new Font("宋体", 12), Brushes.Green, new PointF(x + 15, y + 10));

            gg.DrawEllipse(p, new Rectangle(10, 10, bm.Width - 20, bm.Height - 20));
            gg.DrawEllipse(p, new Rectangle(30, 30, bm.Width - 60, bm.Height - 60));

            if(i== t)
            {
                gg.DrawLine(p, new Point((int)(bm.Width / 2), (int)(bm.Height / 2)), new Point(x, y));
            }

        }
        

        PointF[] pointFs = new PointF[100];
        double r = -Math.PI;
        bool status = false;
        for (i = 0; i < pointFs.Length; i++)
        {
            x = 330 + (int)(303 * Math.Cos(r));
            y = 330 + (int)(290 * Math.Sin(r));
            if (status)
                y += 3;
            else
                y -= 3;
            status = !status;
            pointFs[i] = new PointF(x, y);
            r -= 0.01;
        }
        gg.DrawLines(p, pointFs);
    }, 1f, 1f, 0, 0);
    //bm.Save(@"C:\\Users\\JS114295\\Desktop\\images\kkk1.jpg", ImageFormat.Jpeg);
    this.pictureBox1.Image = bm;