C#实现图片切割的方法

public class ImageManager{  /// <summary>  /// 图像切割  /// </summary>  /// <param name="url">图像文件名称</param>  /// <param name="width">切割后图像宽度</param>  /// <param name="height">切割后图像高度</param>  /// <param name="savePath">切割后图像文件保存路径</param>  /// <param name="fileExt">切割后图像文件扩展名</param>  public static void Cut(string url, int width, int height,string savePath,string fileExt,string logofile)  {   Bitmap bitmap = new Bitmap(url);   Decimal MaxRow = Math.Ceiling((Decimal)bitmap.Height / height);   Decimal MaxColumn = Math.Ceiling((decimal)bitmap.Width / width);   for (decimal i = 0; i < MaxRow; i++)   {    for (decimal j = 0; j < MaxColumn; j++)    {     string filename = i.ToString() + "," + j.ToString() + "." + fileExt;     Bitmap bmp = new Bitmap(width, height);     for (int offsetX = 0; offsetX < width; offsetX++)     {      for (int offsetY = 0; offsetY < height; offsetY++)      {       if (((j * width + offsetX) < bitmap.Width) && ((i * height + offsetY) < bitmap.Height))       {        bmp.SetPixel(offsetX, offsetY, bitmap.GetPixel((int)(j * width + offsetX), (int)(i * height + offsetY)));       }      }     }     Graphics g = Graphics.FromImage(bmp);     g.DrawString("武林网", new Font("黑体", 20), new SolidBrush(Color.FromArgb(70, Color.WhiteSmoke)), 60, height/2);//加水印     ImageFormat format = ImageFormat.Png;     switch (fileExt.ToLower())     {      case "png":       format = ImageFormat.Png;       break;      case "bmp":       format = ImageFormat.Bmp;       break;      case "gif":       format = ImageFormat.Gif;       break;     }     bmp.Save(savePath+"//" + filename,format);    }   }  }}