webfunction.cs

小E单班同学录系统

            Bitmap b = new Bitmap(image.Width, image.Height);
            try
            {
                Graphics g = Graphics.FromImage(b);
                g.Clear(Color.White);
                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                g.DrawImage(image, 0, 0, image.Width, image.Height);
                if (ShowWatermark)
                {
                    switch (WatermarkType)
                    {
                        //是图片的话               
                        case "I":
                            addWatermarkImage(g, System.Web.HttpContext.Current.Server.MapPath(Watermarkimgpath), WatermarkPosition, image.Width, image.Height);
                            break;
                        //如果是文字                    
                        case "T":
                            WatermarkText += System.Configuration.ConfigurationManager.AppSettings["WaterImgText"].ToString();
                            addWatermarkText(g, WatermarkText, WatermarkPosition, image.Width, image.Height);
                            break;
                    }


                }

            }
            catch (Exception e)
            {
                if (File.Exists(oldpath))
                {
                    File.Delete(oldpath);
                }
            }
            finally
            {
                b.Save(newpath, System.Drawing.Imaging.ImageFormat.Jpeg);
                b.Dispose();
                image.Dispose();
                if (File.Exists(oldpath))
                {
                    File.Delete(oldpath);
                }
            }
        }

        /// <summary>
        ///  加水印文字
        /// </summary>
        /// <param name="picture">imge 对象</param>
        /// <param name="_watermarkText">水印文字内容</param>
        /// <param name="_watermarkPosition">水印位置 TL TR BR BL</param>
        /// <param name="_width">被加水印图片的宽</param>
        /// <param name="_height">被加水印图片的高</param>
        public void addWatermarkText(Graphics picture, string _watermarkText, string _watermarkPosition, int _width, int _height)
        {
            int[] sizes = new int[] { 12, 10, 8, 6, 4 };
            Font crFont = null;
            SizeF crSize = new SizeF();
            for (int n = 0; n < sizes.Length; n++)
            {
                crFont = new Font("arial", sizes[n], FontStyle.Bold);
                crSize = picture.MeasureString(_watermarkText, crFont);

                if ((ushort)crSize.Width < (ushort)_width)
                    break;
            }

            float xpos = 0;
            float ypos = 0;

            switch (_watermarkPosition)
            {
                case "TL":
                    xpos = ((float)_width * (float).01) + (crSize.Width / 2);
                    ypos = (float)_height * (float).01;
                    break;
                case "TR":
                    xpos = ((float)_width * (float).99) - (crSize.Width / 2);
                    ypos = (float)_height * (float).01;
                    break;
                case "BR":
                    xpos = ((float)_width * (float).99) - (crSize.Width / 2);
                    ypos = ((float)_height * (float).99) - crSize.Height;
                    break;
                case "BL":
                    xpos = ((float)_width * (float).01) + (crSize.Width / 2);
                    ypos = ((float)_height * (float).99) - crSize.Height;
                    break;
            }

            StringFormat StrFormat = new StringFormat();
            StrFormat.Alignment = StringAlignment.Center;

            SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
            picture.DrawString(_watermarkText, crFont, semiTransBrush2, xpos + 1, ypos + 1, StrFormat);

            SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
            picture.DrawString(_watermarkText, crFont, semiTransBrush, xpos, ypos, StrFormat);


            semiTransBrush2.Dispose();
            semiTransBrush.Dispose();
        }

        /**/
        /// <summary>
        ///  加水印图片
        /// </summary>
        /// <param name="picture">imge 对象</param>
        /// <param name="WaterMarkPicPath">水印图片的地址</param>
        /// <param name="_watermarkPosition">水印位置 TL TR BL BR</param>
        /// <param name="_width">被加水印图片的宽</param>
        /// <param name="_height">被加水印图片的高</param>
        public void addWatermarkImage(Graphics picture, string WaterMarkPicPath, string _watermarkPosition, int _width, int _height)
        {
            System.Drawing.Image watermark = new Bitmap(WaterMarkPicPath);
            ImageAttributes imageAttributes = new ImageAttributes();
            ColorMap colorMap = new ColorMap();
            colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
            colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
            ColorMap[] remapTable = { colorMap };
            imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
            float[][] colorMatrixElements = {
                                                new float[] {1.0f,  0.0f,  0.0f,  0.0f, 0.0f},
                                                 new float[] {0.0f,  1.0f,  0.0f,  0.0f, 0.0f},
                                                new float[] {0.0f,  0.0f,  1.0f,  0.0f, 0.0f},
                                                new float[] {0.0f,  0.0f,  0.0f,  0.3f, 0.0f},
                                                 new float[] {0.0f,  0.0f,  0.0f,  0.0f, 1.0f}
                                             };

            ColorMatrix colorMatrix = new ColorMatrix(colorMatrixElements);

            imageAttributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);

            int xpos = 0;
            int ypos = 0;
            int WatermarkWidth = 0;
            int WatermarkHeight = 0;
            double bl = 1d;
            //计算水印图片的比率
            //取背景的1/4宽度来比较
            if ((_width > watermark.Width * 4) && (_height > watermark.Height * 4))
            {
                bl = 1;
            }
            else if ((_width > watermark.Width * 4) && (_height < watermark.Height * 4))
            {
                bl = Convert.ToDouble(_height / 4) / Convert.ToDouble(watermark.Height);

            }
            else

                if ((_width < watermark.Width * 4) && (_height > watermark.Height * 4))
                {
                    bl = Convert.ToDouble(_width / 4) / Convert.ToDouble(watermark.Width);
                }
                else
                {
                    if ((_width * watermark.Height) > (_height * watermark.Width))
                    {
                        bl = Convert.ToDouble(_height / 4) / Convert.ToDouble(watermark.Height);

                    }
                    else
                    {
                        bl = Convert.ToDouble(_width / 4) / Convert.ToDouble(watermark.Width);

                    }

                }

            WatermarkWidth = Convert.ToInt32(watermark.Width * bl);
            WatermarkHeight = Convert.ToInt32(watermark.Height * bl);



            switch (_watermarkPosition)
            {
                case "TL":
                    xpos = 10;
                    ypos = 10;
                    break;
                case "TR":
                    xpos = _width - WatermarkWidth - 10;
                    ypos = 10;
                    break;
                case "BR":
                    xpos = _width - WatermarkWidth - 10;
                    ypos = _height - WatermarkHeight - 10;
                    break;
                case "BL":
                    xpos = 10;
                    ypos = _height - WatermarkHeight - 10;
                    break;
            }

            picture.DrawImage(watermark, new Rectangle(xpos, ypos, WatermarkWidth, WatermarkHeight), 0, 0, watermark.Width, watermark.Height, GraphicsUnit.Pixel, imageAttributes);


            watermark.Dispose();
            imageAttributes.Dispose();
        }

        /**/
        /// <summary>
        /// 生成缩略图
        /// </summary>
        /// <param name="originalImagePath">原图片地址</param>
        /// <param name="thumbnailPath">新图片地址</param>
        /// <param name="tWidth">缩略图的宽</param>
        /// <param name="tHeight">缩略图的高</param>
        /// <param name="Mode">W H Cut</param>
        public void GreateMiniImage(string originalImagePath, string thumbnailPath, int width, int height, string Mode)
        {
            System.Drawing.Image originalImage = null;
            System.Drawing.Image bitmap = null;
            try
            {
                originalImage = System.Drawing.Image.FromFile(originalImagePath);
                int towidth = width;
                int toheight = height;

                int x = 0;
                int y = 0;
                int ow = originalImage.Width;
                int oh = originalImage.Height;

                switch (Mode)
                {
                    case "HW"://指定高宽缩放（可能变形）                
                        break;
                    case "W"://指定宽，高按比例                    
                        toheight = originalImage.Height * width / originalImage.Width;
                        break;
                    case "H"://指定高，宽按比例
                        towidth = originalImage.Width * height / originalImage.Height;
                        break;
                    case "Cut"://指定高宽裁减（不变形） 
                        if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                        {
                            oh = originalImage.Height;
                            ow = originalImage.Height * towidth / toheight;
                            y = 0;
                            x = (originalImage.Width - ow) / 2;
                        }
                        else
                        {
                            ow = originalImage.Width;
                            oh = originalImage.Width * height / towidth;
                            x = 0;
                            y = (originalImage.Height - oh) / 2;
                        }
                        break;
                    default:
                        break;
                }

                //新建一个bmp图片
                bitmap = new System.Drawing.Bitmap(towidth, toheight);

                //新建一个画板
                Graphics g = System.Drawing.Graphics.FromImage(bitmap);

                //设置高质量插值法
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

                //设置高质量,低速度呈现平滑程度
                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

                //清空画布并以透明背景色填充
                g.Clear(Color.Transparent);

                //在指定位置并且按指定大小绘制原图片的指定部分
                g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight), new Rectangle(x, y, ow, oh), GraphicsUnit.Pixel);

                //以jpg格式保存缩略图
                bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch (Exception e)
            {
                LeeHom.Error.Record("生成缩略图", e.ToString());
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();
            }
        }
    }
}