添加水印（文字and图片）

/// <summary>
        /// 返回新的后缀
        /// </summary>
        /// <param name="fromFileStream">文件流</param>
        /// <param name="fileSaveUrl">保存地址，后缀为gif,png,jpg，所有其它后缀会统一改成jpg</param>
        /// <param name="templateWidth">最大宽度</param>
        /// <param name="templateHeight">最大高度</param>
        /// <param name="jpgQuality">压缩质量</param>
        /// <returns></returns>
        public static string MakeSmallImg(System.IO.Stream fromFileStream, string fileSaveUrl, System.Double templateWidth, System.Double templateHeight, int jpgQuality)
        {
            //从文件取得图片对象，并使用流中嵌入的颜色管理信息
            System.Drawing.Image myImage = System.Drawing.Image.FromStream(fromFileStream, true);
            //缩略图宽、高
            System.Double newWidth = myImage.Width, newHeight = myImage.Height;
            //宽大于模版的横图
            if (myImage.Width >= myImage.Height)
            {
                if (myImage.Width > templateWidth)
                {
                    //宽按模版，高按比例缩放
                    newWidth = templateWidth;
                    newHeight = myImage.Height * (newWidth / myImage.Width);
                }
            }
            //高大于模版的竖图
            else
            {
                if (myImage.Height > templateHeight)
                {
                    //高按模版，宽按比例缩放
                    newHeight = templateHeight;
                    newWidth = myImage.Width * (newHeight / myImage.Height);
                }
            }
            //取得图片大小
            System.Drawing.Size mySize = new Size((int)newWidth, (int)newHeight);
            //新建一个bmp图片
            System.Drawing.Image bitmap = new System.Drawing.Bitmap(mySize.Width, mySize.Height);
            //新建一个画板
            System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

            g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
            //设置高质量插值法
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            //设置高质量,低速度呈现平滑程度
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //清空一下画布
            g.Clear(Color.Transparent);
            //在指定位置画图
            g.DrawImage(myImage, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height),
            new System.Drawing.Rectangle(0, 0, myImage.Width, myImage.Height),
            System.Drawing.GraphicsUnit.Pixel);
            ///文字水印
            //System.Drawing.Graphics G=System.Drawing.Graphics.FromImage(bitmap);
            //System.Drawing.Font f=new Font("宋体",10);
            //System.Drawing.Brush b=new SolidBrush(Color.Black);
            //G.DrawString("myohmine",f,b,10,10);
            //G.Dispose();
            ///图片水印
            //System.Drawing.Image copyImage = System.Drawing.Image.FromFile(System.Web.HttpContext.Current.Server.MapPath("pic/1.gif"));
            //Graphics a = Graphics.FromImage(bitmap);
            //a.DrawImage(copyImage, new Rectangle(bitmap.Width-copyImage.Width,bitmap.Height-copyImage.Height,copyImage.Width, copyImage.Height),0,0, copyImage.Width, copyImage.Height, GraphicsUnit.Pixel);
            //copyImage.Dispose();
            //a.Dispose();
            //copyImage.Dispose();
            //保存缩略图
            int i = fileSaveUrl.LastIndexOf('.');
            string name = fileSaveUrl.Substring(0, i);
            string exten = fileSaveUrl.Substring(i + 1).ToLower();
            ImageFormat format = ImageFormat.Jpeg;
            switch (exten)
            {
                case "png": format = ImageFormat.Png; break;
                case "gif": format = ImageFormat.Gif; break;
                default: exten = "jpg"; fileSaveUrl = name + ".jpg"; break;
            }
            if (File.Exists(fileSaveUrl)) { File.Delete(fileSaveUrl); }
            if (format == ImageFormat.Jpeg)
            {
                EncoderParameters encoderParams = new EncoderParameters();
                long[] quality = new long[1];
                quality[0] = jpgQuality;
                EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
                encoderParams.Param[0] = encoderParam;
                //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象.
                ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
                ImageCodecInfo jpegICI = null;
                for (int x = 0;
                x < arrayICI.Length;
                x++)
                {
                    if (arrayICI[x].FormatDescription.Equals("JPEG"))
                    {
                        jpegICI = arrayICI[x];
                        //设置JPEG编码
                        break;
                    }
                }

                bitmap.Save(fileSaveUrl, jpegICI, encoderParams);
            }
            else
            {
                bitmap.Save(fileSaveUrl, format);
            }
            g.Dispose();
            myImage.Dispose();
            bitmap.Dispose();
            return exten;
        }

//处理图片上传
            var fileCtl = FV.Row.FindControl("fuPicture") as FileUpload;
            if (fileCtl.HasFile)
            {
                //上传图片

                string path = (EditPersonalCode == "New" ? EditOrgCode : e.Keys["OrgCode"].ToString()).Replace('.', '/');
                string fix = fileCtl.FileName.Substring(fileCtl.FileName.LastIndexOf('.') + 1).ToLower();
                if (fix != "jpg" && fix != "png" && fix != "bmp" && fix != "gif")
                {
                    e.Cancel = true;
                    ShowAlert("请重新选择照片上传\\n错误的图片格式：" + fix);
                    return;
                }

                string photoFilePath = Server.MapPath("~/OrgData/") + path;
                if (!Directory.Exists(photoFilePath)) //如果不存在就建立
                {
                    Directory.CreateDirectory(photoFilePath);
                }

                string fname = string.Format("s_{0}_{1}", e.Keys["PersonalCode"], DateTime.Now.TimeOfDay.TotalSeconds);
                string newName = string.Format("{0}.{1}", fname, fix);//提示：必须用e.Keys["PersonalCode"]而不是EditPersonalCode

                string fullpath = photoFilePath + "\\" + newName;
                try
                {
                    fix = Web.Base.ExtendClass.MakeSmallImg(fileCtl.FileContent, fullpath, 180, 240, 100);
                }
                catch
                {
                    e.Cancel = true;
                    ShowAlert("无法识别的图片");
                    return;
                }
                newName = string.Format("{0}.{1}", fname, fix);//重新改变了后缀
                e.NewValues.Add("PhotoFile", path + "/" + newName);
            }