/// <summary>

        /// 生成缩略图

        /// </summary>

        /// <param name="originalImagePath">源路径</param>

        /// <param name="thumbnailPath">目标路径</param>

        /// <param name="width">宽</param>

        /// <param name="height">高</param>

        /// <param name="mode">缩略模式</param>

        public static Image MakeThumbnail(string originalImagePath, 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（不变形）              &nb