C# 图片添加水印
突然想试试图片水印的功能，就在网上收集了一些，记录下来，便于以后学习。
创建一个类，调用其方法即可，可根据自己需求修改代码。
using System; using System.Web; using System.Drawing; using System.Drawing.Imaging; using System.Drawing.Drawing2D; using System.IO; namespace WaterMarkCommon { public class WaterMark { /// <summary> /// 图片水印 /// </summary> /// <param name="imgPath">服务器图片相对路径</param> /// <param name="filename">保存文件名</param> /// <param name="watermarkFilename">水印文件相对路径</param> /// <param name="watermarkStatus">图片水印位置 0=不使用 1=左上 2=中上 3=右上 4=左中 9=右下</param> /// <param name="quality">附加水印图片质量,0-100</param> /// <param name="watermarkTransparency">水印的透明度 1--10 10为不透明</param> public static void AddImageSignPic(string imgPath, string filename, string watermarkFilename, int watermarkStatus, int quality, int watermarkTransparency) { if(!File.Exists(GetMapPath(imgPath))) return; byte[] _ImageBytes = File.ReadAllBytes(GetMapPath(imgPath)); Image img = Image.FromStream(new System.IO.MemoryStream(_ImageBytes)); filename = GetMapPath(filename); if (watermarkFilename.StartsWith("/") == false) watermarkFilename = "/" + watermarkFilename; watermarkFilename =GetMapPath(watermarkFilename); if (!File.Exists(watermarkFilename)) return; Graphics g = Graphics.FromImage(img); //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; Image watermark = new Bitmap(watermarkFilename); if (watermark.Height >= img.Height || watermark.Width >= img.Width) return; 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 transparency = 0.5F; if (watermarkTransparency >= 1 && watermarkTransparency <= 10) transparency = (watermarkTransparency / 10.0F); 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, transparency, 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; switch (watermarkStatus) { case 1: xpos = (int)(img.Width * (float).01); ypos = (int)(img.Height * (float).01); break; case 2: xpos = (int)((img.Width * (float).50) - (watermark.Width / 2)); ypos = (int)(img.Height * (float).01); break; case 3: xpos = (int)((img.Width * (float).99) - (watermark.Width)); ypos = (int)(img.Height * (float).01); break; case 4: xpos = (int)(img.Width * (float).01); ypos = (int)((img.Height * (float).50) - (watermark.Height / 2)); break; case 5: xpos = (int)((img.Width * (float).50) - (watermark.Width / 2)); ypos = (int)((img.Height * (float).50) - (watermark.Height / 2)); break; case 6: xpos = (int)((img.Width * (float).99) - (watermark.Width)); ypos = (int)((img.Height * (float).50) - (watermark.Height / 2)); break; case 7: xpos = (int)(img.Width * (float).01); ypos = (int)((img.Height * (float).99) - watermark.Height); break; case 8: xpos = (int)((img.Width * (float).50) - (watermark.Width / 2)); ypos = (int)((img.Height * (float).99) - watermark.Height); break; case 9: xpos = (int)((img.Width * (float).99) - (watermark.Width)); ypos = (int)((img.Height * (float).99) - watermark.Height); break; } g.DrawImage(watermark, new Rectangle(xpos, ypos, watermark.Width, watermark.Height), 0, 0, watermark.Width, watermark.Height, GraphicsUnit.Pixel, imageAttributes); ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo ici = null; foreach (ImageCodecInfo codec in codecs) { if (codec.MimeType.IndexOf("jpeg") > -1) ici = codec; } EncoderParameters encoderParams = new EncoderParameters(); long[] qualityParam = new long[1]; if (quality < 0 || quality > 100) quality = 80; qualityParam[0] = quality; EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam); encoderParams.Param[0] = encoderParam; if (ici != null) img.Save(filename, ici, encoderParams); else img.Save(filename); g.Dispose(); img.Dispose(); watermark.Dispose(); imageAttributes.Dispose(); } /// <summary> /// 文字水印 /// </summary> /// <param name="imgPath">服务器图片相对路径</param> /// <param name="filename">保存文件名</param> /// <param name="watermarkText">水印文字</param> /// <param name="watermarkStatus">图片水印位置 0=不使用 1=左上 2=中上 3=右上 4=左中 9=右下</param> /// <param name="quality">附加水印图片质量,0-100</param> /// <param name="fontsize">字体大小</param> /// <param name="fontname">字体</param> public static void AddImageSignText(string imgPath, string filename, string watermarkText, int watermarkStatus, int quality, int fontsize ,string fontname = "微软雅黑") { byte[] _ImageBytes = File.ReadAllBytes(GetMapPath(imgPath)); Image img = Image.FromStream(new System.IO.MemoryStream(_ImageBytes)); filename = GetMapPath(filename); Graphics g = Graphics.FromImage(img); Font drawFont = new Font(fontname, fontsize, FontStyle.Regular, GraphicsUnit.Pixel); SizeF crSize; crSize = g.MeasureString(watermarkText, drawFont); float xpos = 0; float ypos = 0; switch (watermarkStatus) { case 1: xpos = (float)img.Width * (float).01; ypos = (float)img.Height * (float).01; break; case 2: xpos = ((float)img.Width * (float).50) - (crSize.Width / 2); ypos = (float)img.Height * (float).01; break; case 3: xpos = ((float)img.Width * (float).99) - crSize.Width; ypos = (float)img.Height * (float).01; break; case 4: xpos = (float)img.Width * (float).01; ypos = ((float)img.Height * (float).50) - (crSize.Height / 2); break; case 5: xpos = ((float)img.Width * (float).50) - (crSize.Width / 2); ypos = ((float)img.Height * (float).50) - (crSize.Height / 2); break; case 6: xpos = ((float)img.Width * (float).99) - crSize.Width; ypos = ((float)img.Height * (float).50) - (crSize.Height / 2); break; case 7: xpos = (float)img.Width * (float).01; ypos = ((float)img.Height * (float).99) - crSize.Height; break; case 8: xpos = ((float)img.Width * (float).50) - (crSize.Width / 2); ypos = ((float)img.Height * (float).99) - crSize.Height; break; case 9: xpos = ((float)img.Width * (float).99) - crSize.Width; ypos = ((float)img.Height * (float).99) - crSize.Height; break; } g.DrawString(watermarkText, drawFont, new SolidBrush(Color.White), xpos + 1, ypos + 1); g.DrawString(watermarkText, drawFont, new SolidBrush(Color.Black), xpos, ypos); ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo ici = null; foreach (ImageCodecInfo codec in codecs) { if (codec.MimeType.IndexOf("jpeg") > -1) ici = codec; } EncoderParameters encoderParams = new EncoderParameters(); long[] qualityParam = new long[1]; if (quality < 0 || quality > 100) quality = 80; qualityParam[0] = quality; EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam); encoderParams.Param[0] = encoderParam; if (ici != null) img.Save(filename, ici, encoderParams); else img.Save(filename); g.Dispose(); img.Dispose(); } #region 获得当前绝对路径 /// <summary> /// 获得当前绝对路径 /// </summary> /// <param name="strPath">指定的路径</param> /// <returns>绝对路径</returns> public static string GetMapPath(string strPath) { if (strPath.ToLower().StartsWith("http://")) { return strPath; } if (HttpContext.Current != null) { return HttpContext.Current.Server.MapPath(strPath); } else //非web程序引用 { strPath = strPath.Replace("/", "\\"); if (strPath.StartsWith("\\")) { strPath = strPath.Substring(strPath.IndexOf('\\', 1)).TrimStart('\\'); } return System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, strPath); } } #endregion } }
