public void GetImg()         {            var imgPath = @"C:\Users\Public\Pictures\Sample Pictures\Koala.jpg";            System.Drawing.Image image = new System.Drawing.Bitmap(imgPath);            //   int iStep = 100;            int iStep = 256;            int iLeft = 0, iTop = 0, iWidth = iStep, iHeight = iStep;            for (int i = 0; i < image.Height / iStep; i++)            {                iTop = i * iStep;                for (int j = 0; j < image.Width / iStep; j++)                {                    iLeft = j * iStep;                    // 目标区域                    Rectangle destRect = new Rectangle(0, 0, iWidth, iHeight);                    // 源图区域                    Rectangle srcRect = new Rectangle(iLeft, iTop, iWidth, iHeight);                    // 新建Graphics对象                    Bitmap newImage = new Bitmap(iWidth, iHeight);                    Graphics g = Graphics.FromImage(newImage);                    // 绘图平滑程序                    g.SmoothingMode = SmoothingMode.HighQuality;                    // 图片输出质量                    g.CompositingQuality = CompositingQuality.HighQuality;                    // 输出到newImage对象                    g.DrawImage(image, destRect, srcRect, GraphicsUnit.Pixel);                    // 释放绘图对象                    g.Dispose();                    string strDestFile = string.Format(                     "{0}//x{1}y{2}.jpg",                     imgPath, iLeft, iTop, iStep                     );                    newImage.Save(strDestFile);                }            }        }