ASP.NET2.0 生成缩略图

protected void btnUploadPicture_Click1(object sender, EventArgs e)    {        //检查上传文件的格式是否有效        if (this.UploadFile.PostedFile.ContentType.ToLower().IndexOf("image") < 0)        {            Response.Write("上传图片格式无效！");            return;        }

        //生成原图        Byte[] oFileByte = new byte[this.UploadFile.PostedFile.ContentLength];        System.IO.Stream oStream = this.UploadFile.PostedFile.InputStream;        Byte[] aa = this.UploadFile.FileBytes;        System.Drawing.Image oImage = System.Drawing.Image.FromStream(oStream);

        int oWidth = oImage.Width; //原图宽度        int oHeight = oImage.Height; //原图高度        int tWidth = 100; //设置缩略图初始宽度        int tHeight = 100; //设置缩略图初始高度

        //按比例计算出缩略图的宽度和高度        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)));        }

        //生成缩略原图        Bitmap tImage = new Bitmap(tWidth, tHeight);        Graphics g = Graphics.FromImage(tImage);        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; //设置高质量插值法        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度        g.Clear(Color.Transparent); //清空画布并以透明背景色填充        g.DrawImage(oImage, new Rectangle(0, 0, tWidth, tHeight), new Rectangle(0, 0, oWidth, oHeight), GraphicsUnit.Pixel);

        string oFullName = Server.MapPath(".") + "/" + "o" + DateTime.Now.ToShortDateString().Replace("-", "") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + ".jpg"; //保存原图的物理路径        string tFullName = Server.MapPath(".") + "/" + "t" + DateTime.Now.ToShortDateString().Replace("-", "") + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + ".jpg"; //保存缩略图的物理路径

        try        {            //以JPG格式保存图片            oImage.Save(oFullName, System.Drawing.Imaging.ImageFormat.Jpeg);            tImage.Save(tFullName, System.Drawing.Imaging.ImageFormat.Jpeg);            //Response.BinaryWrite(aa);            //Response.WriteFile(oFullName);            //Response.WriteFile(tFullName);        }        catch (Exception ex)        {            throw ex;        }        finally        {            //释放资源            oImage.Dispose();            g.Dispose();            tImage.Dispose();        }    }