水印相关（转载）

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Drawing.Drawing2D;

namespace JillZhang
{

    public enum MarkType
     {
        Text,Image
    }
    /**//// <summary>
    /// 给图片添加水印得类得描述
    /// </summary>
    public class WaterMark
     {
        ---------------------成员变量---------------------#region ---------------------成员变量---------------------        
        private string _text="";
        private string _imgPath="";
        private int _markX=0;
        private int _markY=0;
        private float _transparency=1;
        private string _fontFamily="宋体";
        private Color _textColor=Color.Black;
        private bool _textbold=false;
        int[] sizes=new int[] {48,32,16,8,6,4};
        private Image _image=null;
        private Image _markedIamge=null;
        private MarkType _markType=MarkType.Text;
        #endregion

        ---------------------构造函数---------------------#region ---------------------构造函数---------------------
        /**//// <summary>
        /// 实例化一个水印类
        /// </summary>
        public WaterMark()
         {
            
        }
        /**//// <summary>
        ///　初始化一个只添加文字水印得实例
        /// </summary>
        /// <param name="text">水印文字</param>
        /// <param name="fontFamily">文字字体</param>
        /// <param name="bold">是否粗体</param>
        /// <param name="color">字体颜色</param>
        /// <param name="markX">标记位置横坐标</param>
        /// <param name="markY">标记位置纵坐标</param>
        public WaterMark(string text,string fontFamily,bool bold,Color color,int markX,int markY)
         {    
            this._markType=MarkType.Text;
            this._text=text;
            this._fontFamily=fontFamily;
            this._textbold=bold;
            this._textColor=color;
            this._markX=markX;
            this._markY=MarkY;
            this.Mark();
        }
        /**//// <summary>
        /// 实例化一个只添加图片水印得实例
        /// </summary>
        /// <param name="imagePath">水印图片路径</param>
        /// <param name="tranparence">透明度</param>
        /// <param name="markX">标记位置横坐标</param>
        /// <param name="markY">标记位置纵坐标</param>
        public WaterMark(string imagePath,float tranparence,int markX,int markY)
         {
            this._markType=MarkType.Image;        
            this._imgPath=imagePath;
            this._markX=markX;
            this._markY=MarkY;
            this._transparency=tranparence;
            this.Mark();
        }
        #endregion

        ---------------------公共属性---------------------#region ---------------------公共属性---------------------
        /**//// <summary>
        /// 水印类型
        /// </summary>
        public MarkType WaterMarkType
         {
            get
             {
                return _markType;
            }
            set
             {
                _markType=value;
            }
        }        
        /**//// <summary>
        /// 文字水印得内容
        /// </summary>
        public string Text
         {
            get {return _text;}
            set {_text=value;}
        }
        /**//// <summary>
        /// 水印图片得路径
        /// </summary>
        public string WaterImagePath
         {
            get
             {
                return _imgPath;
            }
            set
             {
                this._imgPath=value;
            }
        }
        /**//// <summary>
        /// 水印图片
        /// </summary>
        public Image WaterImage
         {
            get
             {
                try
                 {
                    return Image.FromFile(this.WaterImagePath);
                }
                catch
                 {
                    return null;
                }
                }            
        }
        /**//// <summary>
        /// 添加水印位置得横坐标
        /// </summary>
        public int MarkX
         {
            get {return _markX;}
            set {_markX=value;}
        }
        /**//// <summary>
        /// 添加水印位置得纵坐标
        /// </summary>
        public int MarkY
         {
            get {return _markY;}
            set {_markY=value;}
        }
        /**//// <summary>
        /// 水印得透明度
        /// </summary>
        public float Transparency
         {
            get
             {
                if(_transparency>1.0f)
                 {
                    _transparency=1.0f;
                }
                return _transparency;}
            set {_transparency=value;}
        }
        /**//// <summary>
        /// 水印文字得颜色
        /// </summary>
        public Color TextColor
         {
            get {return _textColor;}
            set {_textColor=value;}
        }
        /**//// <summary>
        /// 水印文字得字体
        /// </summary>
        public string TextFontFamilyStr
         {
            get {return _fontFamily;}
            set {_fontFamily=value;}
        }
        public FontFamily TextFontFamily
         {
            get {return new FontFamily(this.TextFontFamilyStr);}
        }
        /**//// <summary>
        /// 水印文字是否加粗
        /// </summary>
        public bool Bold
         {
            get {return _textbold;}
            set {_textbold=value;}
        }
        /**//// <summary>
        /// 原图
        /// </summary>
    　　public Image SourceImage
       {
          get
           {
              return _image;
          }
          set
           {
              _image=value;
          }
      }
        /**//// <summary>
        /// 加过水印之后得图
        /// </summary>
        public Image MarkedImage
         {
            get
             {
                return this._markedIamge;
            }            
        }

        #endregion

        ---------------------方法事件---------------------#region ---------------------方法事件---------------------
        public Image Mark(Image img,MarkType markType,string text,Image waterImg,int markx,int marky,
            bool bold,Color textColor,float transparence,FontFamily fontFamily)
         {
            //首先先判断该图片是否是 gif动画，如果为gif动画不对图片进行改动
        
            foreach(Guid guid in img.FrameDimensionsList)
             {
                FrameDimension dimension= new FrameDimension(guid);
                if(img.GetFrameCount(dimension)>1)
                 {
                    return img;
                }
            }
            try
             {
                //添加文字水印
                if(markType==MarkType.Text)
                 {
                    //根据源图片生成新的Bitmap对象作为作图区，为了给gif图片添加水印，才有此周折
                    Bitmap newBitmap=new Bitmap(img.Width,img.Height,PixelFormat.Format24bppRgb); 
                    //设置新建位图得分辨率
                    newBitmap.SetResolution(img.HorizontalResolution,img.VerticalResolution);
                    //创建Graphics对象，以对该位图进行操作
                    Graphics g = Graphics.FromImage(newBitmap);
                    //消除锯齿
                    g.SmoothingMode=SmoothingMode.AntiAlias;
                    //将原图拷贝到作图区
                    g.DrawImage(img,new Rectangle(0,0,img.Width,img.Height),0,0,img.Width,img.Height,GraphicsUnit.Pixel);
                    //声明字体对象
                    Font cFont = null;
                    //用来测试水印文本长度得尺子
                    SizeF size=new SizeF();
                    //探测出一个适合图片大小得字体大小，以适应水印文字大小得自适应
                    for(int i=0;i<6;i++)
                     {
                        //创建一个字体对象
                        cFont= new Font(fontFamily,sizes[i]);
                        //是否加粗
                        if(!bold)
                         {
                            cFont= new Font(fontFamily,sizes[i],FontStyle.Regular);
                        }
                        else
                         {
                            cFont=new Font(fontFamily,sizes[i],FontStyle.Bold);
                        }
                        //测量文本大小
                        size=g.MeasureString(this.Text,cFont);
                        //匹配第一个符合要求得字体大小
                        if((ushort)size.Width<(ushort)img.Width)
                         {
                            break;
                        }
                    }
                    //创建刷子对象，准备给图片写上文字
                    Brush brush= new SolidBrush(textColor);
                    //在指定得位置写上文字
                    g.DrawString(text,cFont,brush,markx,marky);
                    //释放Graphics对象
                    g.Dispose();   
                    //将生成得图片读入MemoryStream
                    System.IO.MemoryStream ms = new System.IO.MemoryStream();
                    newBitmap.Save(ms,ImageFormat.Jpeg);
                    //重新生成Image对象
                    img=System.Drawing.Image.FromStream(ms);    
                    //返回新的Image对象
                    return img;

                }
                //添加图像水印
                else if(markType==MarkType.Image)
                 {
                    //获得水印图像
                    Image markImg = waterImg;
                    //创建颜色矩阵
                    float[][] ptsArray = { 
                                            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, transparence, 0}, //注意：此处为0.0f为完全透明，1.0f为完全不透明
                                            new float[]  {0, 0, 0, 0, 1}}; 
                    ColorMatrix colorMatrix= new ColorMatrix(ptsArray);
                    //新建一个Image属性
                    ImageAttributes imageAttributes= new ImageAttributes();
                    //将颜色矩阵添加到属性
                    imageAttributes.SetColorMatrix(colorMatrix,ColorMatrixFlag.Default,
                        ColorAdjustType.Default);
                    //生成位图作图区
                    Bitmap newBitmap=new Bitmap(img.Width,img.Height,PixelFormat.Format24bppRgb);
                    //设置分辨率
                    newBitmap.SetResolution(img.HorizontalResolution,img.VerticalResolution);
                    //创建Graphics
                    Graphics g = Graphics.FromImage(newBitmap);
                    //消除锯齿
                    g.SmoothingMode=SmoothingMode.AntiAlias;
                    //拷贝原图到作图区
                    g.DrawImage(img,new Rectangle(0,0,img.Width,img.Height),0,0,img.Width,img.Height,GraphicsUnit.Pixel);
                    //如果原图过小
                    if(markImg.Width>img.Width||markImg.Height>img.Height)
                     {
                        System.Drawing.Image.GetThumbnailImageAbort callb=null;
                        //对水印图片生成缩略图,缩小到原图得1/4
                        System.Drawing.Image new_img=markImg.GetThumbnailImage(img.Width/4,markImg.Height*img.Width/markImg.Width,callb,new System.IntPtr());
                        //添加水印
                        g.DrawImage(new_img,new Rectangle(markx,marky,new_img.Width,new_img.Height),0,0,new_img.Width,new_img.Height,GraphicsUnit.Pixel,imageAttributes);
                        //释放缩略图
                        new_img.Dispose();
                        //释放Graphics
                        g.Dispose();
                        //将生成得图片读入MemoryStream
                        System.IO.MemoryStream ms = new System.IO.MemoryStream();
                        newBitmap.Save(ms,ImageFormat.Jpeg);
　　　　　　　　　　//返回新的Image对象
                        img=Image.FromStream(ms);
                        return img;
                    }
                        //原图足够大
                    else
                     {
                        //添加水印
                        g.DrawImage(markImg,new Rectangle(markx,marky,markI        mg.Width,markImg.Height),0,0,markImg.Width,markImg.Height,GraphicsUnit.Pixel,imageAttributes);
                        //释放Graphics
                        g.Dispose();
                        //将生成得图片读入MemoryStream
                        System.IO.MemoryStream ms = new System.IO.MemoryStream();
                        newBitmap.Save(ms,ImageFormat.Jpeg);
                        //返回新的Image对象
                        img=Image.FromStream(ms);
                        return img;
                    }                    
                }
                return img;
            }
            catch
             {
                return img;   
            }            

        }
        /**//// <summary>
        /// 添加水印，此方法适用于gif格式得图片
        /// </summary>
        /// <param name="image">需要添加水印得图片</param>
        /// <returns>添加水印之后得图片</returns>
        private void Mark()
         {
            this._markedIamge=Mark(this.SourceImage,this.WaterMarkType,this._text,this.WaterImage,this._markX,this._markY,this._textbold,this._textColor,this._transparency,this.TextFontFamily);
        }
        #endregion        
    }
}