索引像素格式的图像的setPixel问题

改变：

// 对比

Color colorBefore = image.GetPixel(5, 5);

BitmapData data = image.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.WriteOnly, PixelFormat.Format8bppIndexed);

// 将图像转化为byte数组

byte[] bytes = newbyte[data.Height * data.Stride];
Marshal.Copy(data.Scan0, bytes, 0, bytes.Length);

bytes[5 * data.Stride + 5] = 1; // Set the pixel at (5, 5) to the color #1// Copy the bytes from the byte array into the image
Marshal.Copy(bytes, 0, data.Scan0, bytes.Length);

image.UnlockBits(data);

// You can check the pixel has been changed
Color colorAfter = image.GetPixel(5, 5);

Console.WriteLine("Pixel changed from {0} to {1}.", colorBefore, colorAfter);