/// <summary>

        /// 生成缩略图

        /// </summary>

        /// <param name="orginalImagePat">原图片地址</param>

        /// <param name="thumNailPath">缩略图地址</param>

        /// <param name="width">缩略图宽度</param>

        /// <param name="height">缩略图高度</param>

        /// <param name="model">生成缩略的模式</param>

        public void MakeThumNail(string originalImagePath, string thumNailPath, int width, int height, string model)

        {

            System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);

            int thumWidth = width;      //缩略图的宽度

            int thumHeight = height;    //缩略图的高度

            int x = ;

            int y = ;

            int originalWidth = originalImage.Width;    //原始图片的宽度

            int originalHeight = originalImage.Height;  //原始图片的高度

            switch (model)

            {

                case "HW":      //指定高宽缩放,可能变形

                    break;

                case "W":       //指定宽度,高度按照比例缩放

                    thumHeight = originalImage.Height * width / originalImage.Width;

                    break;

                case "H":       //指定高度,宽度按照等比例缩放

                    thumWidth = originalImage.Width * height / originalImage.Height;

                    break;

                case "Cut":

                    if ((double)originalImage.Width / (double)originalImage.Height > (double)thumWidth / (double)thumHeight)

                    {

                        originalHeight = originalImage.Height;

                        originalWidth = originalImage.Height * thumWidth / thumHeight;

                        y = ;

                        x = (originalImage.Width - originalWidth) / ;

                    }

                    else

                    {

                        originalWidth = originalImage.Width;

                        originalHeight = originalWidth * height / thumWidth;

                        x = ;

                        y = (originalImage.Height - originalHeight) / ;

                    }

                    break;

                default:

                    break;

            }

            //新建一个bmp图片

            System.Drawing.Image bitmap = new System.Drawing.Bitmap(thumWidth, thumHeight);

            //新建一个画板

            System.Drawing.Graphics graphic = System.Drawing.Graphics.FromImage(bitmap);

            //设置高质量查值法

            graphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

            //设置高质量，低速度呈现平滑程度

            graphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

            //清空画布并以透明背景色填充

            graphic.Clear(System.Drawing.Color.Transparent);

            //在指定位置并且按指定大小绘制原图片的指定部分

            graphic.DrawImage(originalImage, new System.Drawing.Rectangle(, , thumWidth, thumHeight)

                , new System.Drawing.Rectangle(x, y, originalWidth, originalHeight), System.Drawing.GraphicsUnit.Pixel);

            try

            {

                bitmap.Save(thumNailPath, System.Drawing.Imaging.ImageFormat.Jpeg);

            }

            catch (Exception ex)

            {

                throw ex;

            }

            finally

            {

                originalImage.Dispose();

                bitmap.Dispose();

                graphic.Dispose();

            }

        }