生成缩略图并添加水印

        /// <summary>         /// 生成缩略图 并加水印         /// </summary>         /// <param name="originalImagePath">源图路径（物理路径）</param>         /// <param name="thumbnailPath">缩略图路径（物理路径）</param>         /// <param name="width">缩略图宽度</param>         /// <param name="height">缩略图高度</param>         /// <param name="mode">生成缩略图的方式</param>         public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode){            Image originalImage = Image.FromFile(originalImagePath);            int towidth = width;            int toheight = height;            int x = 0;            int y = 0;            int ow = originalImage.Width;            int oh = originalImage.Height;            switch (mode)            {                case "HW"://指定高宽缩放（可能变形）                     break;                case "W"://指定宽，高按比例                     toheight = originalImage.Height * width / originalImage.Width;                    break;                case "H"://指定高，宽按比例                     towidth = originalImage.Width * height / originalImage.Height;                    break;                case "Cut"://指定高宽裁减                     if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)                    {                        oh = originalImage.Height;                        ow = originalImage.Height * towidth / toheight;                        y = 0;                        x = (originalImage.Width - ow) / 2;                    }                    else                    {                        ow = originalImage.Width;                        oh = originalImage.Width * height / towidth;                        x = 0;                        y = (originalImage.Height - oh) / 2;                    }                    break;                case "CutA"://指定高宽裁减（不变形）自定义                     if (ow <= towidth && oh <= toheight)                    {                        x = -(towidth - ow) / 2;                        y = -(toheight - oh) / 2;                        ow = towidth;                        oh = toheight;                    }                    else                    {                        if (ow > oh)//宽大于高                         {                            x = 0;                            y = -(ow - oh) / 2;                            oh = ow;                        }                        else//高大于宽                         {                            y = 0;                            x = -(oh - ow) / 2;                            ow = oh;                        }                    }                    break;                default:                    break;            }            //新建一个bmp图片             Image bitmap = new System.Drawing.Bitmap(towidth, toheight);            //新建一个画板             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;            //清空画布并以白色背景色填充             g.Clear(Color.White);            //在指定位置并且按指定大小绘制原图片的指定部分             g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),            new Rectangle(x, y, ow, oh),            GraphicsUnit.Pixel);            //文字水印            System.Drawing.Graphics testGrahpics = System.Drawing.Graphics.FromImage(bitmap);            System.Drawing.Font font = new System.Drawing.Font("宋体", 14, System.Drawing.FontStyle.Bold);            System.Drawing.Brush brush = new System.Drawing.SolidBrush(System.Drawing.Color.Gray);            //分行            string sInput = "Idgecn";    //获取输入的水印文字            int coloum = 60;    //获取每行的字符数            //利用循环，来依次输出            for (int i = 0, j = 0; i < sInput.Length; i += coloum, j++)            {                //若要修改水印文字在照片上的位置，可将20修改成你想要的任何值                if (j != sInput.Length / coloum)                {                    string s = sInput.Substring(i, coloum);                    testGrahpics.DrawString(s, font, brush, 110, 10 * (i / coloum + 1));                }                else                {                    string s = sInput.Substring(i, sInput.Length % coloum);                    testGrahpics.DrawString(s, font, brush, 110, 10 * (j + 1));                }            }            testGrahpics.Dispose();            try            {                //以jpg格式保存缩略图                 bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);            }            catch (System.Exception e)            {                throw e;            }            finally            {                originalImage.Dispose();                bitmap.Dispose();                g.Dispose();            }        }