C# 生成缩略图 方法

 #region -生成缩略图-
        /// <summary>
        /// 生成缩略图
        /// </summary>
        /// <param name="orginalImagePath">原图片对象</param>
        /// <param name="thumbnailPath">缩略图的路径</param>
        /// <param name="width">指定宽度</param>
        /// <param name="heigth">指定高度</param>
        /// <param name="model">缩放类型 HW：可以变形 W:指定宽度，高安比例缩放 "H"://指定高度，宽安比例绽放 "Cut"://指定高宽，裁减（不变形）</param>
        public static void MakeThumbnail(Image orginalPric, string thumbnailPath, int width, int heigth, string model)
        {
            Image originalImage = orginalPric;//获得图片对象

            int towidth = width;
            int toheigth = heigth;

            int x = 0;
            int y = 0;

            int ow = originalImage.Width;
            int oh = originalImage.Height;

            #region -缩略图的类型-
            switch (model)
            {
                case "HW"://指定高宽缩放（可以变形）
                    break;
                case "W"://指定宽度，高安比例缩放
                    toheigth = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高度，宽安比例绽放
                    towidth = originalImage.Width * heigth / originalImage.Height;
                    break;
                case "Cut"://指定高宽，裁减（不变形）
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheigth)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheigth;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * towidth / towidth;
                        y = 0;
                        x = (originalImage.Height - oh) / 2;
                    }

                    break;
                default:
                    break;
            }
            #endregion