GDI与GDI+ 贴图性能对比

在做绘图相关工作，由于对显示绘制结果实时性有要求，筛选了GDI ， 与GDI+ 贴图性能。

这里假设在内存中已绘制完成一张图片，现需求显示在控件上，同时，总是更新全部区域。

GDI+ 实现

    private void PainDraw(Bitmap bitmap) {
            pictureBox1.Invalidate();
            //只调用Invalidate() 并非实时更新， 它会合并多个无效区，且延时显示， Update（） 强制更新
            pictureBox1.Update();
        }

    private void pictureBox1_Paint(object sender, PaintEventArgs e)
        {
            i++;
            if (i > 500)
            {
                i = 0;
            }
           e.Graphics.DrawImage(bitmap, new Rectangle(i, 0, bitmap.Width, bitmap.Height));
        }

调用1000次，测帧速

	private void button2_Click(object sender, EventArgs e)
        {
            System.Diagnostics.Stopwatch stopWatch = new System.Diagnostics.Stopwatch();

            path = @"C:\Users\zhoupeng\Pictures\BackgroundDefault.bmp";
            if (bitmap == null)
                bitmap = new Bitmap(path);

            stopWatch.Start();

            for (int i = 0; i < 1000; i++)
            {
                PainDraw(bitmap);
            }

            stopWatch.Stop();

            Console.WriteLine("帧率:{0}", 1000 / (stopWatch.ElapsedMilliseconds / 1000f));

        }

结果：
帧率:88.81783
帧率:91.14108
帧率:92.28497
帧率:83.167

GDI 实现

int i = 0;
        private void SnapShot(PictureBox c, Bitmap bitmapsrc, IntPtr dc1)
        {
            IntPtr dc2 = GetWindowDC(c.Handle);
            i++;
            if (i > 500) {
                i = 0;
            }

            BitBlt(dc2, i, 0, bitmapsrc.Width, bitmapsrc.Height, dc1, 0, 0, TernaryRasterOperations.SRCCOPY);

            DeleteDC(dc2);
        }

    private void button3_Click(object sender, EventArgs e)
        {

            System.Diagnostics.Stopwatch stopWatch = new System.Diagnostics.Stopwatch();

            path = @"C:\Users\zhoupeng\Pictures\BackgroundDefault.bmp";
            if (bitmap == null)
                bitmap = new Bitmap(path);

            stopWatch.Start();
            Graphics g = Graphics.FromImage( bitmap);
            IntPtr dc1 = CreateCompatibleDC(g.GetHdc());
            IntPtr dcbitmap;
            IntPtr pOrig = SelectObject(dc1, dcbitmap = bitmap.GetHbitmap());

            for (int i = 0; i < 1000; i++)
            {
                SnapShot(pictureBox1, bitmap, dc1);
            }

            DeleteDC(dc1);
            DeleteObject(dcbitmap);
            g.ReleaseHdc(dc1);
            g.Dispose();
            stopWatch.Stop();

            Console.WriteLine("帧率:{0}", 1000 / (stopWatch.ElapsedMilliseconds / 1000f));
        }

结果：
帧率:4651.163
帧率:4385.965
帧率:7812.5
帧率:5208.333