上传图片进行压缩并添加文字水印

上网查找的压缩图片代码，经过简单修改将压缩图片和添加文字水印合并在一起

　　　　　/// 添加水印
        /// </summary>
        /// <param name="imgPath">原图片地址</param>
        /// <param name="sImgPath">水印图片地址</param>
        /// <param name="waterMark">水印文字</param>
        /// <param name="isFirstAddWaterMark">是否第一次水印文字</param>
        public static void AddWaterMark(string imgPath, string sImgPath, string waterMark, bool isFirstAddWaterMark = true)
        {
            if (isFirstAddWaterMark && !string.IsNullOrEmpty(waterMark))
            {
                using (Image image = Image.FromFile(imgPath))
                {
                    try
                    {
                        Bitmap bitmap = new Bitmap(image);
                        Color markcolor = Color.Gray;
                        //图片的宽度与高度
                        int width = bitmap.Width, height = bitmap.Height;
                        Graphics g = Graphics.FromImage(bitmap);
                        int rowsNumber, columnsNumber;
                        //图片宽度与高度 用于横向与竖向水印文字
                        if (width > height)
                        {
                            rowsNumber = height / 20;
                            columnsNumber = width / 200;
                        }
                        else
                        {
                            rowsNumber = height / 200;
                            columnsNumber = width / 20;
                        }
                        if (rowsNumber < 1)
                        {
                            rowsNumber = 1;
                        }
                        if (columnsNumber < 1)
                        {
                            columnsNumber = 1;
                        }

                        g.DrawImage(bitmap, 0, 0);
                        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                        g.DrawImage(image, new Rectangle(0, 0, width, height), 0, 0, width, height, GraphicsUnit.Pixel);

                        Font crFont = new Font("微软雅黑", 18, FontStyle.Bold);
                        SizeF crSize = new SizeF();
                        crSize = g.MeasureString(waterMark, crFont);

                        SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(120, 137, 131, 131));

                        //将原点移动 到图片中点
                        g.TranslateTransform(0, height);
                        //以原点为中心 转 -45度
                        g.RotateTransform(-45);

                        for (int j = 0; j < rowsNumber; j++)
                        {
                            for (int i = 0; i < columnsNumber; i++)
                            {
                                g.DrawString(waterMark, crFont, semiTransBrush, new PointF(i * 100 + j * 400, -i * 200 + j * 400));
                            }
                        }

                        //保存文件
                        bitmap.Save(sImgPath, System.Drawing.Imaging.ImageFormat.Jpeg);
                    }
                    catch (Exception e)
                    {
                        throw e;
                    }
                }
            }
        }

　　　　　/// <summary>
        /// 无损压缩图片并添加水印
        /// </summary>
        /// <param name="sFile">原图片地址</param>
        /// <param name="dFile">压缩后保存图片地址</param>
        /// <param name="flag">压缩质量（数字越小压缩率越高）1-100</param>
        /// <param name="size">压缩后图片的最大大小</param>
        /// <param name="sfsc">是否是第一次调用</param>
        /// <param name="waterMark">水印文字</param>
        /// <param name="isFirstAddWaterMark">是否是第一次添加水印</param>
        /// <returns></returns>
        public static bool CompressImage(string sFile, string dFile, int flag = 90, int size = 300, bool sfsc = true, string waterMark = "", bool isFirstAddWaterMark = true)
        {
            Image iSource = Image.FromFile(sFile);
            ImageFormat tFormat = iSource.RawFormat;
            //如果是第一次调用，原始图像的大小小于要压缩的大小，则直接复制文件，并且返回true
            FileInfo firstFileInfo = new FileInfo(sFile);
            if (sfsc == true && firstFileInfo.Length < size * 1024)
            {
                AddWaterMark(sFile, dFile, waterMark, isFirstAddWaterMark);
                return true;
            }

            int dHeight = iSource.Height / 2;
            int dWidth = iSource.Width / 2;
            int sW = 0, sH = 0;
            //按比例缩放
            Size tem_size = new Size(iSource.Width, iSource.Height);
            if (tem_size.Width > dHeight || tem_size.Width > dWidth)
            {
                if ((tem_size.Width * dHeight) > (tem_size.Width * dWidth))
                {
                    sW = dWidth;
                    sH = (dWidth * tem_size.Height) / tem_size.Width;
                }
                else
                {
                    sH = dHeight;
                    sW = (tem_size.Width * dHeight) / tem_size.Height;
                }
            }
            else
            {
                sW = tem_size.Width;
                sH = tem_size.Height;
            }

            Bitmap ob = new Bitmap(dWidth, dHeight);
            Graphics g = Graphics.FromImage(ob);

            g.Clear(Color.WhiteSmoke);
            g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            g.DrawImage(iSource, new Rectangle((dWidth - sW) / 2, (dHeight - sH) / 2, sW, sH), 0, 0, iSource.Width, iSource.Height, GraphicsUnit.Pixel);
            if (isFirstAddWaterMark && !string.IsNullOrEmpty(waterMark))
            {
                //以下代码为保存图片时,添加水印
                Color markcolor = Color.Gray;
                //图片宽度与高度 用于横向与竖向水印文字
                int rowsNumber, columnsNumber;
                if (dWidth > dHeight)
                {
                    rowsNumber = dHeight / 20;
                    columnsNumber = dWidth / 200;
                }
                else
                {
                    rowsNumber = dHeight / 200;
                    columnsNumber = dWidth / 20;
                }
                if (rowsNumber < 1)
                {
                    rowsNumber = 1;
                }
                if (columnsNumber < 1)
                {
                    columnsNumber = 1;
                }

                Font crFont = new Font("微软雅黑", 18, FontStyle.Bold);
                SizeF crSize = new SizeF();
                crSize = g.MeasureString(waterMark, crFont);
                SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(120, 137, 131, 131));
                //将原点移动 到图片中点
                g.TranslateTransform(0, dHeight);
                //以原点为中心 转 -45度
                g.RotateTransform(-45);
                for (int j = 0; j < rowsNumber; j++)
                {
                    for (int i = 0; i < columnsNumber; i++)
                    {
                        g.DrawString(waterMark, crFont, semiTransBrush, new PointF(i * 100 + j * 400, -i * 200 + j * 400));
                    }
                }
            }
            g.Dispose();

            //以下代码为保存图片时，设置压缩质量
            EncoderParameters ep = new EncoderParameters();
            long[] qy = new long[1];
            qy[0] = flag;//设置压缩的比例1-100
            EncoderParameter eParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qy);
            ep.Param[0] = eParam;

            try
            {
                ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
                ImageCodecInfo jpegICIinfo = null;
                for (int x = 0; x < arrayICI.Length; x++)
                {
                    if (arrayICI[x].FormatDescription.Equals("JPEG"))
                    {
                        jpegICIinfo = arrayICI[x];
                        break;
                    }
                }
                if (jpegICIinfo != null)
                {
                    ob.Save(dFile, jpegICIinfo, ep);//dFile是压缩后的新路径
                    FileInfo fi = new FileInfo(dFile);
                    if (fi.Length > 1024 * size)
                    {
                        flag = flag - 10;
                        CompressImage(sFile, dFile, flag, size, false, waterMark, false);
                    }
                }
                else
                {
                    ob.Save(dFile, tFormat);
                }
                return true;
            }
            catch
            {
                return false;
            }
            finally
            {
                iSource.Dispose();
                ob.Dispose();
            }
        }

效果预览：