一段图片处理代码PHP代码转C#代码

Question

        //使用图片为水印
        public static string ReSizePhoto(string filePath, string LogoPath, int width, int height)
        {
            string fileName = System.IO.Path.GetFileName(filePath).ToLower();
            string fileExtension = System.IO.Path.GetExtension(filePath).ToLower();
            string document = System.IO.Path.GetDirectoryName(filePath) + "\\";
            bool check = false;
            switch (fileExtension)
            {
                case ".jpg": check = true;
                    break;
                case ".gif": check = true;
                    break;
                default: check = false;
                    break;
            }            //图片按比例缩放算法
            if (check)
            {
                string saveName = Squirrel.Component.doEncrypt.SMD5(Guid.NewGuid().ToString().Replace("-", "")).Replace("-", "").ToLower().Substring(8, 16) + fileExtension;
                System.Drawing.Image image = System.Drawing.Image.FromFile(filePath);                double h = Convert.ToDouble(image.Height.ToString());
                double w = Convert.ToDouble(image.Width.ToString());
                double bl = h / w;
                if (w > width)
                {
                    if (width == 0 && height != 0)
                    {
                        h = height;
                        w = height * (1 / bl);
                    }
                    else if (width != 0 && height == 0)
                    {
                        w = width;
                        h = width * bl;
                    }
                    else
                    {
                        w = width;
                        h = height;
                    }
                }                //取得图片大小
                System.Drawing.Size size = new Size((int)w, (int)h);
                //新建一个bmp图片
                System.Drawing.Image bitmap = new System.Drawing.Bitmap(size.Width, size.Height);
                //新建一个画板
                System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
                //设置高质量插值法
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                //设置高质量,低速度呈现平滑程度
                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                //清空一下画布
                g.Clear(Color.White);
                //在指定位置画图
                g.DrawImage(image, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height),
                    new System.Drawing.Rectangle(0, 0, image.Width, image.Height),
                    System.Drawing.GraphicsUnit.Pixel);                //图片水印
                System.Drawing.Image copyImage = System.Drawing.Image.FromFile(System.Web.HttpContext.Current.Server.MapPath(LogoPath));
                Graphics a = Graphics.FromImage(bitmap);
                a.DrawImage(copyImage, new Rectangle(bitmap.Width - copyImage.Width, bitmap.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, GraphicsUnit.Pixel);                copyImage.Dispose();
                a.Dispose();
                copyImage.Dispose();                //保存高清晰度的缩略图
                string Path = document + saveName;
                bitmap.Save(Path, System.Drawing.Imaging.ImageFormat.Jpeg);                g.Dispose();
                image.Dispose();
                bitmap.Dispose();                //删除源图片
                Squirrel.Component.doIO.DeletePath(filePath);
                return saveName;
            }
            else
            {
                return fileName;
            }
        }随便贴个混点分