.NET生成高質量縮略圖

 public static string UploadImg(HttpPostedFileBase UploadFile, string path, HttpServerUtilityBase Server)
        {
            Byte[] oFileByte = new byte[UploadFile.ContentLength];
            System.IO.Stream oStream = UploadFile.InputStream;
            System.Drawing.Image oImage = System.Drawing.Image.FromStream(oStream);
            int oWidth = oImage.Width; //原圖寬度
            int oHeight = oImage.Height; //原圖高度
            int tWidth = 100; //設置縮略圖初始寬度
            int tHeight = 100; //設置縮略圖初始高度
            //按比例計算出縮略圖的寬度和高度
            if (oWidth >= oHeight)
            {
                tHeight = (int)Math.Floor(Convert.ToDouble(oHeight) * (Convert.ToDouble(tWidth)
                / Convert.ToDouble(oWidth)));
            }
            else
            {
                tWidth = (int)Math.Floor(Convert.ToDouble(oWidth) * (Convert.ToDouble(tHeight)
                / Convert.ToDouble(oHeight)));
            }
            //生成縮略原圖
            Bitmap tImage = new Bitmap(tWidth, tHeight);
            Graphics g = Graphics.FromImage(tImage);
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            //設置高質量插值法
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //設置高質量,低速度呈現平滑程度
            g.Clear(Color.Transparent); //清空畫布並以透明背景色填充
            g.DrawImage(oImage, new Rectangle(0, 0, tWidth, tHeight),
            new Rectangle(0, 0, oWidth, oHeight), GraphicsUnit.Pixel);
            string tFullName = Server.MapPath(".") + "/" + "t" + DateTime.Now.Hour.ToString()
            + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString()
            + DateTime.Now.Millisecond.ToString() + ".jpg"; //保存縮略圖的物理路徑
            try
            {
                tImage.Save(tFullName, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                g.Dispose();
                tImage.Dispose();
            }
            return tFullName;
        }

//代碼測試沒問題，如果出現GDI+ error 查一下路徑什麼的。