/// 
        ///         /// 
        /// 源图片        /// 缩放后图片宽度        /// 缩放后图片高度        /// 
             public Image GetThumbnail(Image imgSource, int destWidth, int destHeight)        {            int sW = 0, sH = 0;            int sWidth = imgSource.Width;            int sHeight = imgSource.Height;            // 按比例缩放            if (sHeight > destHeight || sWidth > destWidth)            {                if ((sWidth * destHeight) > (sHeight * destWidth))                {                    sW = destWidth;                    sH = (destWidth * sHeight) / sWidth;                }                else                {                    sH = destHeight;                    sW = (sWidth * destHeight) / sHeight;                }            }            else            {                sW = sWidth;                sH = sHeight;            }            Bitmap outBmp = new Bitmap(destWidth, destHeight);            Graphics g = Graphics.FromImage(outBmp);            g.Clear(Color.White);            // 设置画布的描绘质量            g.CompositingQuality = CompositingQuality.HighQuality;            g.SmoothingMode = SmoothingMode.HighQuality;            g.InterpolationMode = InterpolationMode.HighQualityBicubic;            g.DrawImage(imgSource, new Rectangle((destWidth - sW) / 2, (destHeight - sH) / 2, sW, sH), 0, 0, imgSource.Width, imgSource.Height, GraphicsUnit.Pixel);            g.Dispose();            return outBmp;        }