asp .net实现给图片添加图片水印方法示例

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.IO;using System.Collections;using System.Drawing;using System.Drawing.Drawing2D;using System.Drawing.Imaging;namespace ImageWriter{ /// <summary> /// 图片处理类 /// </summary> public class ImageManager { #region 变量声明开始 /// <summary> /// 枚举: 水印位置 /// </summary> public enum WatermarkPosition {  /// <summary>  /// 左上  /// </summary>  LeftTop,  /// <summary>  /// 左中  /// </summary>  Left,  /// <summary>  /// 左下  /// </summary>  LeftBottom,  /// <summary>  /// 正上  /// </summary>  Top,  /// <summary>  /// 正中  /// </summary>  Center,  /// <summary>  /// 正下  /// </summary>  Bottom,  /// <summary>  /// 右上  /// </summary>  RightTop,  /// <summary>  /// 右中  /// </summary>  RightCenter,  /// <summary>  /// 右下  /// </summary>  RigthBottom } #endregion 变量声明结束 #region 构造函数开始 /// <summary> /// 构造函数: 默认 /// </summary> public ImageManager() { } #endregion 构造函数结束 #region 私有函数开始 /// <summary> /// 获取: 图片去扩展名(包含完整路径及其文件名)小写字符串 /// </summary> /// <param name="path">图片路径(包含完整路径,文件名及其扩展名): string</param> /// <returns>返回: 图片去扩展名(包含完整路径及其文件名)小写字符串: string</returns> private string GetFileName(string path) {  return path.Remove(path.LastIndexOf('.')).ToLower(); } /// <summary> /// 获取: 图片以'.'开头的小写字符串扩展名 /// </summary> /// <param name="path">图片路径(包含完整路径,文件名及其扩展名): string</param> /// <returns>返回: 图片以'.'开头的小写字符串扩展名: string</returns> private string GetExtension(string path) {  return path.Remove(0, path.LastIndexOf('.')).ToLower(); } /// <summary> /// 获取: 图片以 '.' 开头的小写字符串扩展名对应的 System.Drawing.Imaging.ImageFormat 对象 /// </summary> /// <param name="format">以 '. '开头的小写字符串扩展名: string</param> /// <returns>返回: 图片以 '.' 开头的小写字符串扩展名对应的 System.Drawing.Imaging.ImageFormat 对象: System.Drawing.Imaging.ImageFormat</returns> private ImageFormat GetImageFormat(string format) {  switch (format)  {  case ".bmp":   return ImageFormat.Bmp;  case ".emf":   return ImageFormat.Emf;  case ".exif":   return ImageFormat.Exif;  case ".gif":   return ImageFormat.Gif;  case ".ico":   return ImageFormat.Icon;  case ".png":   return ImageFormat.Png;  case ".tif":   return ImageFormat.Tiff;  case ".tiff":   return ImageFormat.Tiff;  case ".wmf":   return ImageFormat.Wmf;  default:   return ImageFormat.Jpeg;  } } /// <summary> /// 获取: 枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition 对应的 System.Drawing.Rectangle 对象 /// </summary> /// <param name="positon">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition: Uinatlex.ToolBox.ImageManager.WatermarkPosition</param> /// <param name="X">原图宽度: int</param> /// <param name="Y">原图高度: int</param> /// <param name="x">水印宽度: int</param> /// <param name="y">水印高度: int</param> /// <param name="i">边距: int</param> /// <returns>返回: 枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition 对应的 System.Drawing.Rectangle 对象: System.Drawing.Rectangle</returns> private Rectangle GetWatermarkRectangle(WatermarkPosition positon, int X, int Y, int x, int y, int i) {  switch (positon)  {  case WatermarkPosition.LeftTop:   return new Rectangle(i, i, x, y);  case WatermarkPosition.Left:   return new Rectangle(i, (Y - y) / 2, x, y);  case WatermarkPosition.LeftBottom:   return new Rectangle(i, Y - y - i, x, y);  case WatermarkPosition.Top:   return new Rectangle((X - x) / 2, i, x, y);  case WatermarkPosition.Center:   return new Rectangle((X - x) / 2, (Y - y) / 2, x, y);  case WatermarkPosition.Bottom:   return new Rectangle((X - x) / 2, Y - y - i, x, y);  case WatermarkPosition.RightTop:   return new Rectangle(X - x - i, i, x, y);  case WatermarkPosition.RightCenter:   return new Rectangle(X - x - i, (Y - y) / 2, x, y);  default:   return new Rectangle(X - x - i, Y - y - i, x, y);  } } #endregion 私有函数结束 #region 文字生成开始 #endregion 文字生成结束 #region 设置透明度开始 /// <summary> /// 设置: 图片 System.Drawing.Bitmap 对象透明度 /// </summary> /// <param name="sBitmap">图片 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param> /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param> /// <returns>图片 System.Drawing.Bitmap: System.Drawing.Bitmap</returns> public Bitmap SetTransparence(Bitmap bm, float transparence) {  if (transparence == 0.0f || transparence == 1.0f)  throw new ArgumentException("透明度值只能在0.0f~1.0f之间");  float[][] floatArray =   {  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, transparence, 0.0f },  new float[] { 0.0f, 0.0f, 0.0f, 0.0f, 1.0f }   };  ImageAttributes imageAttributes = new ImageAttributes();  imageAttributes.SetColorMatrix(new ColorMatrix(floatArray), ColorMatrixFlag.Default, ColorAdjustType.Bitmap);  Bitmap bitmap = new Bitmap(bm.Width, bm.Height);  Graphics graphics = Graphics.FromImage(bitmap);  graphics.DrawImage(bm, new Rectangle(0, 0, bm.Width, bm.Height), 0, 0, bm.Width, bm.Height, GraphicsUnit.Pixel, imageAttributes);  graphics.Dispose();  imageAttributes.Dispose();  bm.Dispose();  return bitmap; } /// <summary> /// 设置: 图片 System.Drawing.Bitmap 对象透明度 /// </summary> /// <param name="readpath">图片路径(包含完整路径,文件名及其扩展名): string</param> /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param> /// <returns>图片 System.Drawing.Bitmap: System.Drawing.Bitmap</returns> public Bitmap SetTransparence(string readpath, float transparence) {  return SetTransparence(new Bitmap(readpath), transparence); } #endregion 设置透明度结束 #region 添加水印开始 /// <summary> /// 生成: 原图绘制水印的 System.Drawing.Bitmap 对象 /// </summary> /// <param name="sBitmap">原图 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param> /// <param name="wBitmap">水印 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param> /// <param name="position">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition : Uinatlex.ToolBox.ImageManager.WatermarkPosition</param> /// <param name="margin">水印边距: int</param> /// <returns>返回: 原图绘制水印的 System.Drawing.Bitmap 对象 System.Drawing.Bitmap</returns> public Bitmap CreateWatermark(Bitmap sBitmap, Bitmap wBitmap, WatermarkPosition position, int margin) {  Graphics graphics = Graphics.FromImage(sBitmap);  graphics.DrawImage(wBitmap, GetWatermarkRectangle(position, sBitmap.Width, sBitmap.Height, wBitmap.Width, wBitmap.Height, margin));  graphics.Dispose();  wBitmap.Dispose();  return sBitmap; } #endregion 添加水印结束 #region 图片切割开始 #endregion 图片切割结束 #region 图片缩放开始 #endregion 图片缩放结束 #region 保存图片到文件开始 #region 普通保存开始 /// <summary> /// 保存: System.Drawing.Bitmap 对象到图片文件 /// </summary> /// <param name="bitmap">System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param> /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param> public void Save(Bitmap bitmap, string writepath) {  try  {  bitmap.Save(writepath, GetImageFormat(GetExtension(writepath)));  bitmap.Dispose();  }  catch  {  throw new ArgumentException("图片保存错误");  } } /// <summary> /// 保存: 对象到图片文件 /// </summary> /// <param name="readpath">原图路径(包含完整路径,文件名及其扩展名): string</param> /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param> public void Save(string readpath, string writepath) {  if (string.Compare(readpath, writepath) == 0)  throw new ArgumentException("源图片与目标图片地址相同");  try  {  Save(new Bitmap(readpath), writepath);  }  catch  {  throw new ArgumentException("图片读取错误");  } } #endregion 普通保存结束 #region 文字绘图保存开始 #endregion 文字绘图保存结束 #region 透明度调整保存开始 /// <summary> /// 保存: 设置透明度的对象到图片文件 /// </summary> /// <param name="sBitmap">图片 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param> /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param> /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param> public void SaveTransparence(Bitmap bitmap, float transparence, string writepath) {  Save(SetTransparence(bitmap, transparence), writepath); } /// <summary> /// 保存: 设置透明度的象到图片文件 /// </summary> /// <param name="readpath">原图路径(包含完整路径,文件名及其扩展名): string</param> /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param> /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param> public void SaveTransparence(string readpath, float transparence, string writepath) {  Save(SetTransparence(readpath, transparence), writepath); } #endregion 透明度调整保存结束 #region 水印图片保存开始 /// <summary> /// 保存: 绘制水印的对象到图片文件 /// </summary> /// <param name="sBitmap">原图 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param> /// <param name="wBitmap">水印 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param> /// <param name="position">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition : Uinatlex.ToolBox.ImageManager.WatermarkPosition</param> /// <param name="margin">水印边距: int</param> /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param> public void SaveWatermark(Bitmap sBitmap, Bitmap wBitmap, WatermarkPosition position, int margin, string writepath) {  Save(CreateWatermark(sBitmap, wBitmap, position, margin), writepath); } /// <summary> /// 保存: 绘制水印的对象到图片文件 /// </summary> /// <param name="readpath">图片路径(包含完整路径,文件名及其扩展名): string</param> /// <param name="watermarkpath">水印图片路径(包含完整路径,文件名及其扩展名): string</param> /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param> /// <param name="position">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition : Uinatlex.ToolBox.ImageManager.WatermarkPosition</param> /// <param name="margin">水印边距: int</param> /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param> public void SaveWatermark(string readpath, string watermarkpath, float transparence, WatermarkPosition position, int margin, string writepath) {  if (string.Compare(readpath, writepath) == 0)  throw new ArgumentException("源图片与目标图片地址相同");  if (transparence == 0.0f)  Save(readpath, writepath);  else if (transparence == 1.0f)  SaveWatermark(new Bitmap(readpath), new Bitmap(watermarkpath), position, margin, writepath);  else  SaveWatermark(new Bitmap(readpath), SetTransparence(watermarkpath, transparence), position, margin, writepath); } #endregion 水印图片保存结束 #region 图片切割保存开始 #endregion 图片切割保存结束 #region 图片缩放保存开始 #endregion 图片缩放保存开始 #endregion 保存图片到文件结束 }}/* 调用很简单 im.SaveWatermark(原图地址, 水印地址, 透明度, 水印位置, 边距,保存位置);  Uinatlex.ToolBox.ImageManager im = new Uinatlex.ToolBox.ImageManager(); im.SaveWatermark(Server.MapPath("/原图.jpg"), Server.MapPath("/水印.jpg"), 0.5f, Uinatlex.ToolBox.ImageManager.WatermarkPosition.RigthBottom, 10, Server.MapPath("/原图.jpg")); */

 protected void Page_Load(object sender, EventArgs e) { string newfileName = Server.MapPath("img/") + DateTime.Now.Millisecond + "" + DateTime.Now.Second + ".jpg"; ImageManager im = new ImageManager(); //调用很简单 im.SaveWatermark(原图地址, 水印地址, 透明度, 水印位置, 边距,保存到的位置);  im.SaveWatermark(Server.MapPath("img/Chrysanthemum.jpg"), Server.MapPath("img/woshi.jpg"), 0.9f, ImageManager.WatermarkPosition.RigthBottom, 10, newfileName); }