Example of asp. net method for adding picture watermark to picture

Preface

This article mainly introduced to you is asp. net to add picture watermarking method, attention is the picture watermarking, the need for friends can refer to learning, the following words to see a detailed introduction.

The method is as follows

First of all, write a class to write image watermark, and first create an ImageWriter class library (this class contains enumerated types and methods)

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"));
 */

Call the above class in the client page

 protected void Page_Load(object sender, EventArgs e)
 {
 string newfileName = Server.MapPath("img/") + DateTime.Now.Millisecond + "" + DateTime.Now.Second + ".jpg";
 ImageManager im = new ImageManager();
 // The call is simple  im.SaveWatermark( Original address ,  Watermark address ,  Transparency ,  Watermark location ,  Margins , Location to save to ); 
 im.SaveWatermark(Server.MapPath("img/Chrysanthemum.jpg"), Server.MapPath("img/woshi.jpg"), 0.9f, ImageManager.WatermarkPosition.RigthBottom, 10, newfileName);
 }

Summarize