本文实例为大家分享了C#.NET添加 图片水印的方法，供大家参考，具体内容如下
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
namespace Pub.Class
{
/// <summary>
/// 添加水印类 只支持添加图片水印
/// </summary>
public class Watermark
{
#region 私有成员
private string modifyImagePath= null ;
private string drawedImagePath= null ;
private int rightSpace;
private int bottoamSpace;
private int lucencyPercent=70;
private string outPath= null ;
#endregion
#region 构造器
/// <summary>
/// 构造函数
/// </summary>
public Watermark() { }
#endregion
#region 属性
/// <summary>
/// 获取或设置要修改的图像路径
/// </summary>
public string ModifyImagePath
{
get { return this .modifyImagePath;}
set { this .modifyImagePath=value;}
}
/// <summary>
/// 获取或设置在画的图片路径(水印图片)
/// </summary>
public string DrawedImagePath
{
get { return this .drawedImagePath;}
set { this .drawedImagePath=value;}
}
/// <summary>
/// 获取或设置水印在修改图片中的右边距
/// </summary>
public int RightSpace
{
get { return this .rightSpace;}
set { this .rightSpace=value;}
}
/// <summary>
/// 获取或设置水印在修改图片中距底部的高度
/// </summary>
public int BottoamSpace
{
get { return this .bottoamSpace;}
set { this .bottoamSpace=value;}
}
/// <summary>
/// 获取或设置要绘制水印的透明度,注意是原来图片透明度的百分比
/// </summary>
public int LucencyPercent
{
get { return this .lucencyPercent;}
set { if (value>=0&&value<=100) this .lucencyPercent=value; }
}
/// <summary>
/// 获取或设置要输出图像的路径
/// </summary>
public string OutPath
{
get { return this .outPath;}
set { this .outPath=value;}
}
#endregion
#region 开始绘制水印 DrawImage
/// <summary>
/// 开始绘制水印
/// </summary>
/// <example>
/// <code>
/// Watermark wm = new Watermark();
/// wm.DrawedImagePath= Server.MapPath("") + "/upfile/" + "backlogo.gif";
/// wm.ModifyImagePath=path;
/// wm.RightSpace=184;
/// wm.BottoamSpace=81;
/// wm.LucencyPercent=50;
/// wm.OutPath=Server.MapPath("") + "/upfile/" + fileName + "_new" + extension;
/// wm.DrawImage();
///
/// //保存加水印过后的图片,删除原始图片
/// mFileName=fileName + "_new" + extension;
/// if(File.Exists(path)) { File.Delete(path); }
/// </code>
/// </example>
public void DrawImage()
{
Image modifyImage= null ;
Image drawedImage= null ;
Graphics g= null ;
try {
modifyImage=Image.FromFile( this .ModifyImagePath); //建立图形对象
drawedImage=Image.FromFile( this .DrawedImagePath);
g=Graphics.FromImage(modifyImage);
int x=modifyImage.Width- this .rightSpace; //获取要绘制图形坐标
int y=modifyImage.Height- this .BottoamSpace;
float [][] matrixItems ={ //设置颜色矩阵
new float [] {1, 0, 0, 0, 0},
new float [] {0, 1, 0, 0, 0},
new float [] {0, 0, 1, 0, 0},
new float [] {0, 0, 0, ( float ) this .LucencyPercent/100f, 0},
new float [] {0, 0, 0, 0, 1}};
ColorMatrix colorMatrix = new ColorMatrix(matrixItems);
ImageAttributes imgAttr= new ImageAttributes();
imgAttr.SetColorMatrix(colorMatrix,ColorMatrixFlag.Default,ColorAdjustType.Bitmap);
g.DrawImage( //绘制阴影图像
drawedImage,
new Rectangle(x,y,drawedImage.Width,drawedImage.Height),
0,0,drawedImage.Width,drawedImage.Height,
GraphicsUnit.Pixel,imgAttr);
string [] allowImageType={ ".jpg" , ".gif" , ".png" , ".bmp" , ".tiff" , ".wmf" , ".ico" }; //保存文件
FileInfo file= new FileInfo( this .ModifyImagePath);
ImageFormat imageType=ImageFormat.Gif;
switch (file.Extension.ToLower()) {
case ".jpg" : imageType=ImageFormat.Jpeg; break ;
case ".gif" : imageType=ImageFormat.Gif; break ;
case ".png" : imageType=ImageFormat.Png; break ;
case ".bmp" : imageType=ImageFormat.Bmp; break ;
case ".tif" : imageType=ImageFormat.Tiff; break ;
case ".wmf" : imageType=ImageFormat.Wmf; break ;
case ".ico" : imageType=ImageFormat.Icon; break ;
default : break ;
}
MemoryStream ms= new MemoryStream();
modifyImage.Save(ms,imageType);
byte [] imgData=ms.ToArray();
modifyImage.Dispose();
drawedImage.Dispose();
g.Dispose();
FileStream fs= null ;
if ( this .OutPath== null || this .OutPath== "" ) {
File.Delete( this .ModifyImagePath);
fs= new FileStream( this .ModifyImagePath,FileMode.Create,FileAccess.Write);
} else {
fs= new FileStream( this .OutPath,FileMode.Create,FileAccess.Write);
}
if (fs!= null ) {
fs.Write(imgData,0,imgData.Length);
fs.Close();
}
} finally {
try {
drawedImage.Dispose();
modifyImage.Dispose();
g.Dispose();
} catch {}
}
}
#endregion
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：http://www.cnblogs.com/livexy/archive/2010/07/05/1771714.html
dy("nrwz");