ASP.NET(C#)图片加文字、图片水印(转)

一、图片上加文字:

//using System.Drawing;   
//using System.IO;   
//using System.Drawing.Imaging;   
  
private void AddTextToImg(string fileName,string text)   
{   
   if(!File.Exists(MapPath(fileName)))   
   {   
       throw new FileNotFoundException("The file don't exist!");   
   }   
      
   if( text == string.Empty )   
   {   
       return;   
   }   
   //还需要判断文件类型是否为图像类型,这里就不赘述了   
  
   System.Drawing.Image image = System.Drawing.Image.FromFile(MapPath(fileName));   
   Bitmap bitmap = new Bitmap(image,image.Width,image.Height);   
   Graphics g = Graphics.FromImage(bitmap);   
  
   float fontSize = 12.0f;    //字体大小   
   float textWidth = text.Length*fontSize;  //文本的长度   
   //下面定义一个矩形区域,以后在这个矩形里画上白底黑字   
   float rectX = 0;           
   float rectY = 0;   
   float rectWidth = text.Length*(fontSize+8);   
   float rectHeight = fontSize+8;   
   //声明矩形域   
   RectangleF textArea = new RectangleF(rectX,rectY,rectWidth,rectHeight);   
  
   Font font = new Font("宋体",fontSize);   //定义字体   
   Brush whiteBrush = new SolidBrush(Color.White);   //白笔刷,画文字用   
   Brush blackBrush = new SolidBrush(Color.Black);   //黑笔刷,画背景用   
  
   g.FillRectangle(blackBrush,rectX,rectY,rectWidth,rectHeight);      
  
   g.DrawString(text,font,whiteBrush,textArea);   
   MemoryStream ms = new MemoryStream( );   
   //保存为Jpg类型   
   bitmap.Save(ms,ImageFormat.Jpeg);   
  
   //输出处理后的图像,这里为了演示方便,我将图片显示在页面中了   
   Response.Clear();   
   Response.ContentType = "image/jpeg";   
   Response.BinaryWrite( ms.ToArray() );   
  
   g.Dispose();   
   bitmap.Dispose();   
   image.Dispose();   
}  
//using System.Drawing;
//using System.IO;
//using System.Drawing.Imaging;

private void AddTextToImg(string fileName,string text)
{
   if(!File.Exists(MapPath(fileName)))
   {
       throw new FileNotFoundException("The file don't exist!");
   }
   
   if( text == string.Empty )
   {
       return;
   }
   //还需要判断文件类型是否为图像类型,这里就不赘述了

   System.Drawing.Image image = System.Drawing.Image.FromFile(MapPath(fileName));
   Bitmap bitmap = new Bitmap(image,image.Width,image.Height);
   Graphics g = Graphics.FromImage(bitmap);

   float fontSize = 12.0f;    //字体大小
   float textWidth = text.Length*fontSize;  //文本的长度
   //下面定义一个矩形区域,以后在这个矩形里画上白底黑字
   float rectX = 0;        
   float rectY = 0;
   float rectWidth = text.Length*(fontSize+8);
   float rectHeight = fontSize+8;
   //声明矩形域
   RectangleF textArea = new RectangleF(rectX,rectY,rectWidth,rectHeight);

   Font font = new Font("宋体",fontSize);   //定义字体
   Brush whiteBrush = new SolidBrush(Color.White);   //白笔刷,画文字用
   Brush blackBrush = new SolidBrush(Color.Black);   //黑笔刷,画背景用

   g.FillRectangle(blackBrush,rectX,rectY,rectWidth,rectHeight);  

   g.DrawString(text,font,whiteBrush,textArea);
   MemoryStream ms = new MemoryStream( );
   //保存为Jpg类型
   bitmap.Save(ms,ImageFormat.Jpeg);

   //输出处理后的图像,这里为了演示方便,我将图片显示在页面中了
   Response.Clear();
   Response.ContentType = "image/jpeg";
   Response.BinaryWrite( ms.ToArray() );

   g.Dispose();
   bitmap.Dispose();
   image.Dispose();
}

二、图片上加水印:

 //using System;    
//using System.Web;    
//using System.Drawing;    
//using System.Drawing.Drawing2D;    
//using System.Drawing.Imaging;    
//using System.IO;    
//using System.Reflection;    
  
/// <summary>    
/// 给图片上水印    
/// </summary>    
/// <param name="filePath">原图片地址</param>    
/// <param name="waterFile">水印图片地址</param>    
public void MarkWater(string filePath,string waterFile)    
{    
    //GIF不水印    
    int i = filePath.LastIndexOf(".");    
    string ex = filePath.Substring(i,filePath.Length - i);    
    if(string.Compare(ex,".gif",true) == 0)    
    {    
        return;    
    }    
  
    string ModifyImagePath = BasePath + filePath;//修改的图像路径    
    int lucencyPercent=25;    
    Image modifyImage=null;    
    Image drawedImage=null;    
    Graphics g=null;    
    try    
    {    
        //建立图形对象    
        modifyImage=Image.FromFile(ModifyImagePath,true);    
        drawedImage=Image.FromFile(BasePath + waterFile,true);    
        g=Graphics.FromImage(modifyImage);    
        //获取要绘制图形坐标    
        int x=modifyImage.Width-drawedImage.Width;    
        int y=modifyImage.Height-drawedImage.Height;    
        //设置颜色矩阵    
        float[][] matrixItems ={    
            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)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);    
        //绘制阴影图像    
        g.DrawImage(drawedImage,new Rectangle(x,y,drawedImage.Width,drawedImage.Height),10,10,drawedImage.Width,drawedImage.Height,GraphicsUnit.Pixel,imgAttr);    
        //保存文件    
        string[] allowImageType={".jpg",".gif",".png",".bmp",".tiff",".wmf",".ico"};    
        FileInfo fi=new FileInfo(ModifyImagePath);    
        ImageFormat imageType=ImageFormat.Gif;    
        switch(fi.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;    
        File.Delete(ModifyImagePath);    
        fs=new FileStream(ModifyImagePath,FileMode.Create,FileAccess.Write);    
        if(fs!=null)    
        {    
            fs.Write(imgData,0,imgData.Length);    
            fs.Close();    
        }    
    }    
    finally    
    {    
        try    
        {    
            drawedImage.Dispose();    
            modifyImage.Dispose();    
            g.Dispose();    
        }    
        catch  
        {   
        }    
   }    
}   
//using System; 
//using System.Web; 
//using System.Drawing; 
//using System.Drawing.Drawing2D; 
//using System.Drawing.Imaging; 
//using System.IO; 
//using System.Reflection;

/// <summary> 
/// 给图片上水印 
/// </summary> 
/// <param name="filePath">原图片地址</param> 
/// <param name="waterFile">水印图片地址</param> 
public void MarkWater(string filePath,string waterFile) 

    //GIF不水印 
    int i = filePath.LastIndexOf("."); 
    string ex = filePath.Substring(i,filePath.Length - i); 
    if(string.Compare(ex,".gif",true) == 0) 
    { 
        return; 
    }

    string ModifyImagePath = BasePath + filePath;//修改的图像路径 
    int lucencyPercent=25; 
    Image modifyImage=null; 
    Image drawedImage=null; 
    Graphics g=null; 
    try 
    { 
        //建立图形对象 
        modifyImage=Image.FromFile(ModifyImagePath,true); 
        drawedImage=Image.FromFile(BasePath + waterFile,true); 
        g=Graphics.FromImage(modifyImage); 
        //获取要绘制图形坐标 
        int x=modifyImage.Width-drawedImage.Width; 
        int y=modifyImage.Height-drawedImage.Height; 
        //设置颜色矩阵 
        float[][] matrixItems ={ 
            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)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); 
        //绘制阴影图像 
        g.DrawImage(drawedImage,new Rectangle(x,y,drawedImage.Width,drawedImage.Height),10,10,drawedImage.Width,drawedImage.Height,GraphicsUnit.Pixel,imgAttr); 
        //保存文件 
        string[] allowImageType={".jpg",".gif",".png",".bmp",".tiff",".wmf",".ico"}; 
        FileInfo fi=new FileInfo(ModifyImagePath); 
        ImageFormat imageType=ImageFormat.Gif; 
        switch(fi.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; 
        File.Delete(ModifyImagePath); 
        fs=new FileStream(ModifyImagePath,FileMode.Create,FileAccess.Write); 
        if(fs!=null) 
        { 
            fs.Write(imgData,0,imgData.Length); 
            fs.Close(); 
        } 
    } 
    finally 
    { 
        try 
        { 
            drawedImage.Dispose(); 
            modifyImage.Dispose(); 
            g.Dispose(); 
        } 
        catch
        {
        } 
   } 

四、C#图片水印生成类(图片、文字、透明水印)

/*  
 * 使用说明:  
 *  建议先定义一个WaterImage实例  
 *  然后利用实例的属性,去匹配需要进行操作的参数  
 *  然后定义一个WaterImageManage实例  
 *  利用WaterImageManage实例进行DrawImage(),印图片水印  
 *  DrawWords()印文字水印  
 *   
-*/  
  
using System;   
using System.Drawing;   
using System.Drawing.Imaging;   
using System.Drawing.Drawing2D;   
using System.IO;   
/// <summary>   
/// 图片位置   
/// </summary>   
public enum ImagePosition   
{   
    LeftTop,        //左上   
    LeftBottom,    //左下   
    RightTop,       //右上   
    RigthBottom,  //右下   
    TopMiddle,     //顶部居中   
    BottomMiddle, //底部居中   
    Center           //中心   
}   
  
/// <summary>   
/// 水印图片的操作管理 Design by Gary Gong From Demetersoft.com   
/// </summary>   
public class WaterImageManage   
{   
    /// <summary>   
    /// 生成一个新的水印图片制作实例   
    /// </summary>   
    public WaterImageManage ()   
    {   
        //   
        // TODO: Add constructor logic here   
        //   
    }   
  
    /// <summary>   
    /// 添加图片水印   
    /// </summary>   
    /// <param name="sourcePicture">源图片文件名</param>   
    /// <param name="waterImage">水印图片文件名</param>   
    /// <param name="alpha">透明度(0.1-1.0数值越小透明度越高)</param>   
    /// <param name="position">位置</param>   
    /// <param name="PicturePath" >图片的路径</param>   
    /// <returns>返回生成于指定文件夹下的水印文件名</returns>   
    public string  DrawImage(string sourcePicture,   
                                      string waterImage,   
                                      float alpha,   
                                      ImagePosition position,   
                                      string PicturePath )   
    {   
        //   
        // 判断参数是否有效   
        //   
        if (sourcePicture == string.Empty || waterImage == string.Empty || alpha == 0.0 || PicturePath == string.Empty)   
        {   
            return sourcePicture;   
        }   
  
        //   
        // 源图片,水印图片全路径   
        //   
        string sourcePictureName = PicturePath + sourcePicture;   
        string waterPictureName = PicturePath + waterImage;   
        string fileSourceExtension = System.IO.Path.GetExtension(sourcePictureName).ToLower();   
        string fileWaterExtension = System.IO.Path.GetExtension(waterPictureName).ToLower();   
        //   
        // 判断文件是否存在,以及类型是否正确   
        //   
        if (System.IO.File.Exists(sourcePictureName) == false ||    
            System.IO.File.Exists(waterPictureName) == false ||(   
            fileSourceExtension != ".gif" &&   
            fileSourceExtension != ".jpg" &&   
            fileSourceExtension != ".png") || (   
            fileWaterExtension != ".gif" &&   
            fileWaterExtension != ".jpg" &&   
            fileWaterExtension != ".png")   
            )   
        {   
            return sourcePicture;   
        }   
  
        //   
        // 目标图片名称及全路径   
        //   
        string targetImage = sourcePictureName.Replace ( System.IO.Path.GetExtension(sourcePictureName),"") + "_1101.jpg";   
  
        //   
        // 将需要加上水印的图片装载到Image对象中   
        //   
        Image imgPhoto = Image.FromFile(sourcePictureName);   
        //   
        // 确定其长宽   
        //   
        int phWidth = imgPhoto.Width;   
        int phHeight = imgPhoto.Height;   
  
        //   
        // 封装 GDI+ 位图,此位图由图形图像及其属性的像素数据组成。   
        //   
        Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);   
  
        //   
        // 设定分辨率   
        //    
        bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);   
  
        //   
        // 定义一个绘图画面用来装载位图   
        //   
        Graphics grPhoto = Graphics.FromImage(bmPhoto);   
  
        //   
        //同样,由于水印是图片,我们也需要定义一个Image来装载它   
        //   
        Image imgWatermark = new Bitmap(waterPictureName);   
           
        //   
        // 获取水印图片的高度和宽度   
        //   
        int wmWidth = imgWatermark.Width;   
        int wmHeight = imgWatermark.Height;   
  
        //SmoothingMode:指定是否将平滑处理(消除锯齿)应用于直线、曲线和已填充区域的边缘。   
        // 成员名称   说明    
        // AntiAlias      指定消除锯齿的呈现。     
        // Default        指定不消除锯齿。     
        // HighQuality  指定高质量、低速度呈现。     
        // HighSpeed   指定高速度、低质量呈现。     
        // Invalid        指定一个无效模式。     
        // None          指定不消除锯齿。    
        grPhoto.SmoothingMode = SmoothingMode.AntiAlias;   
  
        //   
        // 第一次描绘,将我们的底图描绘在绘图画面上   
        //   
        grPhoto.DrawImage(imgPhoto,                                             
                                    new Rectangle(0, 0, phWidth, phHeight),    
                                    0,        
                                    0,          
                                    phWidth,      
                                    phHeight,         
                                    GraphicsUnit.Pixel);       
  
        //   
        // 与底图一样,我们需要一个位图来装载水印图片。并设定其分辨率   
        //   
        Bitmap bmWatermark = new Bitmap(bmPhoto);   
        bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);   
           
        //   
        // 继续,将水印图片装载到一个绘图画面grWatermark   
        //   
        Graphics grWatermark = Graphics.FromImage(bmWatermark);   
  
        //   
        //ImageAttributes 对象包含有关在呈现时如何操作位图和图元文件颜色的信息。   
        //          
        ImageAttributes imageAttributes = new ImageAttributes();   
  
        //   
        //Colormap: 定义转换颜色的映射   
        //   
        ColorMap colorMap = new ColorMap();   
  
        //   
        //我的水印图被定义成拥有绿色背景色的图片被替换成透明   
        //   
        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[][] colorMatrixElements = {    
           new float[] {1.0f,  0.0f,  0.0f,  0.0f, 0.0f}, // red红色   
           new float[] {0.0f,  1.0f,  0.0f,  0.0f, 0.0f}, //green绿色   
           new float[] {0.0f,  0.0f,  1.0f,  0.0f, 0.0f}, //blue蓝色          
           new float[] {0.0f,  0.0f,  0.0f,  alpha, 0.0f}, //透明度        
           new float[] {0.0f,  0.0f,  0.0f,  0.0f, 1.0f}};//   
  
        //  ColorMatrix:定义包含 RGBA 空间坐标的 5 x 5 矩阵。   
        //  ImageAttributes 类的若干方法通过使用颜色矩阵调整图像颜色。   
        ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);   
  
  
        imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,   
         ColorAdjustType.Bitmap);   
  
        //   
        //上面设置完颜色,下面开始设置位置   
        //   
        int xPosOfWm;   
        int yPosOfWm;    
  
        switch (position)   
        {   
            case ImagePosition .BottomMiddle :   
                xPosOfWm = (phWidth-wmWidth ) / 2 ;   
                yPosOfWm = phHeight- wmHeight -10;   
                break ;   
            case ImagePosition .Center :   
                xPosOfWm = (phWidth - wmWidth) / 2;   
                yPosOfWm = (phHeight-wmHeight ) / 2;   
                break ;   
            case ImagePosition .LeftBottom :   
                xPosOfWm = 10;   
                yPosOfWm = phHeight - wmHeight - 10;   
                break ;   
            case ImagePosition .LeftTop :   
                xPosOfWm = 10;   
                yPosOfWm = 10;   
                break;   
            case ImagePosition .RightTop :   
                xPosOfWm = phWidth - wmWidth - 10;   
                yPosOfWm = 10;   
                break ;   
            case ImagePosition .RigthBottom :   
                xPosOfWm = phWidth - wmWidth - 10;   
                yPosOfWm = phHeight - wmHeight - 10;   
                break ;   
            case ImagePosition.TopMiddle :   
                xPosOfWm = (phWidth - wmWidth) / 2;   
                yPosOfWm = 10;   
                break ;   
            default:   
                xPosOfWm = 10;   
                yPosOfWm = phHeight - wmHeight - 10;   
                break;   
        }   
  
        //   
        // 第二次绘图,把水印印上去   
        //   
        grWatermark.DrawImage(imgWatermark,   
         new Rectangle(xPosOfWm,   
                             yPosOfWm,   
                             wmWidth,   
                             wmHeight),    
                             0,                 
                             0,             
                             wmWidth,     
                             wmHeight,      
                             GraphicsUnit.Pixel,     
                             imageAttributes);    
  
          
        imgPhoto = bmWatermark;   
        grPhoto.Dispose();   
        grWatermark.Dispose();   
  
        //   
        // 保存文件到服务器的文件夹里面   
        //   
        imgPhoto.Save(targetImage, ImageFormat.Jpeg);   
        imgPhoto.Dispose();   
        imgWatermark.Dispose();   
        return targetImage.Replace (PicturePath,"");   
    }   
  
    /// <summary>   
    /// 在图片上添加水印文字   
    /// </summary>   
    /// <param name="sourcePicture">源图片文件</param>   
    /// <param name="waterWords">需要添加到图片上的文字</param>   
    /// <param name="alpha">透明度</param>   
    /// <param name="position">位置</param>   
    /// <param name="PicturePath">文件路径</param>   
    /// <returns></returns>   
    public string DrawWords(string sourcePicture,   
                                      string waterWords,   
                                      float alpha,   
                                      ImagePosition position,   
                                      string PicturePath)   
    {   
        //   
        // 判断参数是否有效   
        //   
        if (sourcePicture == string.Empty || waterWords == string.Empty || alpha == 0.0 || PicturePath == string.Empty)   
        {   
            return sourcePicture;   
        }   
  
        //   
        // 源图片全路径   
        //   
        string sourcePictureName = PicturePath + sourcePicture;   
        string fileExtension = System.IO.Path.GetExtension(sourcePictureName).ToLower();   
  
        //   
        // 判断文件是否存在,以及文件名是否正确   
        //   
        if (System.IO.File.Exists(sourcePictureName) == false || (   
            fileExtension != ".gif"  &&   
            fileExtension != ".jpg" &&   
            fileExtension != ".png" ))   
        {   
            return sourcePicture;   
        }   
  
        //   
        // 目标图片名称及全路径   
        //   
        string targetImage = sourcePictureName.Replace(System.IO.Path.GetExtension(sourcePictureName), "") + "_0703.jpg";   
  
        //创建一个图片对象用来装载要被添加水印的图片   
        Image imgPhoto = Image.FromFile(sourcePictureName);   
  
        //获取图片的宽和高   
        int phWidth = imgPhoto.Width;   
        int phHeight = imgPhoto.Height;   
  
        //   
        //建立一个bitmap,和我们需要加水印的图片一样大小   
        Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);   
  
        //SetResolution:设置此 Bitmap 的分辨率   
        //这里直接将我们需要添加水印的图片的分辨率赋给了bitmap   
        bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);   
  
        //Graphics:封装一个 GDI+ 绘图图面。   
        Graphics grPhoto = Graphics.FromImage(bmPhoto);   
  
        //设置图形的品质   
        grPhoto.SmoothingMode = SmoothingMode.AntiAlias;   
  
        //将我们要添加水印的图片按照原始大小描绘(复制)到图形中   
        grPhoto.DrawImage(   
         imgPhoto,                                           //   要添加水印的图片   
         new Rectangle(0, 0, phWidth, phHeight), //  根据要添加的水印图片的宽和高   
         0,                                                     //  X方向从0点开始描绘   
         0,                                                     // Y方向    
         phWidth,                                            //  X方向描绘长度   
         phHeight,                                           //  Y方向描绘长度   
         GraphicsUnit.Pixel);                              // 描绘的单位,这里用的是像素   
  
        //根据图片的大小我们来确定添加上去的文字的大小   
        //在这里我们定义一个数组来确定   
        int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 };   
  
        //字体   
        Font crFont = null;   
        //矩形的宽度和高度,SizeF有三个属性,分别为Height高,width宽,IsEmpty是否为空   
        SizeF crSize = new SizeF();   
  
        //利用一个循环语句来选择我们要添加文字的型号   
        //直到它的长度比图片的宽度小   
        for (int i = 0; i < 7; i++)   
        {   
            crFont = new Font("arial", sizes[i], FontStyle.Bold);   
  
            //测量用指定的 Font 对象绘制并用指定的 StringFormat 对象格式化的指定字符串。   
            crSize = grPhoto.MeasureString(waterWords, crFont);   
  
            // ushort 关键字表示一种整数数据类型   
            if ((ushort)crSize.Width < (ushort)phWidth)   
                break;   
        }   
  
        //截边5%的距离,定义文字显示(由于不同的图片显示的高和宽不同,所以按百分比截取)   
        int yPixlesFromBottom = (int)(phHeight * .05);   
  
        //定义在图片上文字的位置   
        float wmHeight =  crSize.Height;   
        float wmWidth = crSize .Width ;   
  
        float  xPosOfWm;   
        float  yPosOfWm;    
  
        switch (position)   
        {   
            case ImagePosition .BottomMiddle :   
                xPosOfWm = phWidth / 2 ;   
                yPosOfWm = phHeight- wmHeight -10;   
                break ;   
            case ImagePosition .Center :   
                xPosOfWm = phWidth / 2;   
                yPosOfWm = phHeight / 2;   
                break ;   
            case ImagePosition .LeftBottom :   
                xPosOfWm = wmWidth;   
                yPosOfWm = phHeight - wmHeight - 10;   
                break ;   
            case ImagePosition .LeftTop :   
                xPosOfWm = wmWidth/2 ;   
                yPosOfWm = wmHeight / 2;   
                break;   
            case ImagePosition .RightTop :   
                xPosOfWm = phWidth - wmWidth - 10;   
                yPosOfWm = wmHeight;   
                break ;   
            case ImagePosition .RigthBottom :   
                xPosOfWm = phWidth - wmWidth - 10;   
                yPosOfWm = phHeight - wmHeight - 10;   
                break ;   
            case ImagePosition.TopMiddle :   
                xPosOfWm = phWidth / 2;   
                yPosOfWm = wmWidth;   
                break ;   
            default:   
                xPosOfWm = wmWidth;   
                yPosOfWm = phHeight - wmHeight - 10;   
                break;   
        }   
  
        //封装文本布局信息(如对齐、文字方向和 Tab 停靠位),显示操作(如省略号插入和国家标准 (National) 数字替换)和 OpenType 功能。   
        StringFormat StrFormat = new StringFormat();   
  
        //定义需要印的文字居中对齐   
        StrFormat.Alignment = StringAlignment.Center;   
  
        //SolidBrush:定义单色画笔。画笔用于填充图形形状,如矩形、椭圆、扇形、多边形和封闭路径。   
        //这个画笔为描绘阴影的画笔,呈灰色   
        int m_alpha = Convert .ToInt32 ( 256 * alpha);   
        SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(m_alpha, 0, 0, 0));   
  
        //描绘文字信息,这个图层向右和向下偏移一个像素,表示阴影效果   
        //DrawString 在指定矩形并且用指定的 Brush 和 Font 对象绘制指定的文本字符串。   
        grPhoto.DrawString(waterWords,                                    //string of text   
                                   crFont,                                         //font   
                                   semiTransBrush2,                            //Brush   
                                   new PointF(xPosOfWm + 1, yPosOfWm + 1),  //Position   
                                   StrFormat);   
  
        //从四个 ARGB 分量(alpha、红色、绿色和蓝色)值创建 Color 结构,这里设置透明度为153   
        //这个画笔为描绘正式文字的笔刷,呈白色   
        SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));   
  
        //第二次绘制这个图形,建立在第一次描绘的基础上   
        grPhoto.DrawString(waterWords,                 //string of text   
                                   crFont,                                   //font   
                                   semiTransBrush,                           //Brush   
                                   new PointF(xPosOfWm, yPosOfWm),  //Position   
                                   StrFormat);   
  
        //imgPhoto是我们建立的用来装载最终图形的Image对象   
        //bmPhoto是我们用来制作图形的容器,为Bitmap对象   
        imgPhoto = bmPhoto;   
        //释放资源,将定义的Graphics实例grPhoto释放,grPhoto功德圆满   
        grPhoto.Dispose();   
  
        //将grPhoto保存   
        imgPhoto.Save(targetImage, ImageFormat.Jpeg);   
        imgPhoto.Dispose();   
  
        return targetImage.Replace(PicturePath, "");   
    }   
}   
  
/// <summary>   
/// 装载水印图片的相关信息   
/// </summary>   
public class WaterImage   
{   
    public WaterImage ()   
    {   
  
    }   
  
    private string m_sourcePicture;   
    /// <summary>   
    /// 源图片地址名字(带后缀)   
    /// </summary>   
    public string SourcePicture   
    {   
        get { return m_sourcePicture; }   
        set { m_sourcePicture = value; }   
    }   
  
    private string  m_waterImager;   
    /// <summary>   
    /// 水印图片名字(带后缀)   
    /// </summary>   
    public string  WaterPicture   
    {   
        get { return m_waterImager; }   
        set { m_waterImager = value; }   
    }   
  
    private float  m_alpha;   
    /// <summary>   
    /// 水印图片文字的透明度   
    /// </summary>   
    public float  Alpha   
    {   
        get { return m_alpha; }   
        set { m_alpha = value; }   
    }   
  
    private ImagePosition  m_postition;   
    /// <summary>   
    /// 水印图片或文字在图片中的位置   
    /// </summary>   
    public ImagePosition  Position   
    {   
        get { return m_postition; }   
        set { m_postition = value; }   
    }   
  
    private string  m_words;   
    /// <summary>   
    /// 水印文字的内容   
    /// </summary>   
    public string  Words   
    {   
        get { return m_words; }   
        set { m_words = value; }   
    }   
        
}  
/*
 * 
 * 使用说明:
 *  建议先定义一个WaterImage实例
 *  然后利用实例的属性,去匹配需要进行操作的参数
 *  然后定义一个WaterImageManage实例
 *  利用WaterImageManage实例进行DrawImage(),印图片水印
 *  DrawWords()印文字水印
 * 
-*/

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.IO;
/// <summary>
/// 图片位置
/// </summary>
public enum ImagePosition
{
    LeftTop,        //左上
    LeftBottom,    //左下
    RightTop,       //右上
    RigthBottom,  //右下
    TopMiddle,     //顶部居中
    BottomMiddle, //底部居中
    Center           //中心
}

/// <summary>
/// 水印图片的操作管理 Design by Gary Gong From Demetersoft.com
/// </summary>
public class WaterImageManage
{
    /// <summary>
    /// 生成一个新的水印图片制作实例
    /// </summary>
 public WaterImageManage ()
 {
  //
  // TODO: Add constructor logic here
  //
 }

    /// <summary>
    /// 添加图片水印
    /// </summary>
    /// <param name="sourcePicture">源图片文件名</param>
    /// <param name="waterImage">水印图片文件名</param>
    /// <param name="alpha">透明度(0.1-1.0数值越小透明度越高)</param>
    /// <param name="position">位置</param>
    /// <param name="PicturePath" >图片的路径</param>
    /// <returns>返回生成于指定文件夹下的水印文件名</returns>
    public string  DrawImage(string sourcePicture,
                                      string waterImage,
                                      float alpha,
                                      ImagePosition position,
                                      string PicturePath )
    {
        //
        // 判断参数是否有效
        //
        if (sourcePicture == string.Empty || waterImage == string.Empty || alpha == 0.0 || PicturePath == string.Empty)
        {
            return sourcePicture;
        }

        //
        // 源图片,水印图片全路径
        //
        string sourcePictureName = PicturePath + sourcePicture;
        string waterPictureName = PicturePath + waterImage;
        string fileSourceExtension = System.IO.Path.GetExtension(sourcePictureName).ToLower();
        string fileWaterExtension = System.IO.Path.GetExtension(waterPictureName).ToLower();
        //
        // 判断文件是否存在,以及类型是否正确
        //
        if (System.IO.File.Exists(sourcePictureName) == false || 
            System.IO.File.Exists(waterPictureName) == false ||(
            fileSourceExtension != ".gif" &&
            fileSourceExtension != ".jpg" &&
            fileSourceExtension != ".png") || (
            fileWaterExtension != ".gif" &&
            fileWaterExtension != ".jpg" &&
            fileWaterExtension != ".png")
            )
        {
            return sourcePicture;
        }

        //
        // 目标图片名称及全路径
        //
        string targetImage = sourcePictureName.Replace ( System.IO.Path.GetExtension(sourcePictureName),"") + "_1101.jpg";

        //
        // 将需要加上水印的图片装载到Image对象中
        //
        Image imgPhoto = Image.FromFile(sourcePictureName);
        //
        // 确定其长宽
        //
        int phWidth = imgPhoto.Width;
        int phHeight = imgPhoto.Height;

        //
        // 封装 GDI+ 位图,此位图由图形图像及其属性的像素数据组成。
        //
        Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);

        //
        // 设定分辨率
        // 
        bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

        //
        // 定义一个绘图画面用来装载位图
        //
        Graphics grPhoto = Graphics.FromImage(bmPhoto);

        //
        //同样,由于水印是图片,我们也需要定义一个Image来装载它
        //
        Image imgWatermark = new Bitmap(waterPictureName);
        
        //
        // 获取水印图片的高度和宽度
        //
        int wmWidth = imgWatermark.Width;
        int wmHeight = imgWatermark.Height;

        //SmoothingMode:指定是否将平滑处理(消除锯齿)应用于直线、曲线和已填充区域的边缘。
        // 成员名称   说明 
        // AntiAlias      指定消除锯齿的呈现。  
        // Default        指定不消除锯齿。  
        // HighQuality  指定高质量、低速度呈现。  
        // HighSpeed   指定高速度、低质量呈现。  
        // Invalid        指定一个无效模式。  
        // None          指定不消除锯齿。 
        grPhoto.SmoothingMode = SmoothingMode.AntiAlias;

        //
        // 第一次描绘,将我们的底图描绘在绘图画面上
        //
        grPhoto.DrawImage(imgPhoto,                                          
                                    new Rectangle(0, 0, phWidth, phHeight), 
                                    0,     
                                    0,       
                                    phWidth,   
                                    phHeight,      
                                    GraphicsUnit.Pixel);   

        //
        // 与底图一样,我们需要一个位图来装载水印图片。并设定其分辨率
        //
        Bitmap bmWatermark = new Bitmap(bmPhoto);
        bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
        
        //
        // 继续,将水印图片装载到一个绘图画面grWatermark
        //
        Graphics grWatermark = Graphics.FromImage(bmWatermark);

        //
        //ImageAttributes 对象包含有关在呈现时如何操作位图和图元文件颜色的信息。
        //       
        ImageAttributes imageAttributes = new ImageAttributes();

        //
        //Colormap: 定义转换颜色的映射
        //
        ColorMap colorMap = new ColorMap();

        //
        //我的水印图被定义成拥有绿色背景色的图片被替换成透明
        //
        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[][] colorMatrixElements = { 
           new float[] {1.0f,  0.0f,  0.0f,  0.0f, 0.0f}, // red红色
           new float[] {0.0f,  1.0f,  0.0f,  0.0f, 0.0f}, //green绿色
           new float[] {0.0f,  0.0f,  1.0f,  0.0f, 0.0f}, //blue蓝色       
           new float[] {0.0f,  0.0f,  0.0f,  alpha, 0.0f}, //透明度     
           new float[] {0.0f,  0.0f,  0.0f,  0.0f, 1.0f}};//

        //  ColorMatrix:定义包含 RGBA 空间坐标的 5 x 5 矩阵。
        //  ImageAttributes 类的若干方法通过使用颜色矩阵调整图像颜色。
        ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);


        imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default,
         ColorAdjustType.Bitmap);

        //
        //上面设置完颜色,下面开始设置位置
        //
        int xPosOfWm;
        int yPosOfWm;

        switch (position)
        {
            case ImagePosition .BottomMiddle :
                xPosOfWm = (phWidth-wmWidth ) / 2 ;
                yPosOfWm = phHeight- wmHeight -10;
                break ;
            case ImagePosition .Center :
                xPosOfWm = (phWidth - wmWidth) / 2;
                yPosOfWm = (phHeight-wmHeight ) / 2;
                break ;
            case ImagePosition .LeftBottom :
                xPosOfWm = 10;
                yPosOfWm = phHeight - wmHeight - 10;
                break ;
            case ImagePosition .LeftTop :
                xPosOfWm = 10;
                yPosOfWm = 10;
                break;
            case ImagePosition .RightTop :
                xPosOfWm = phWidth - wmWidth - 10;
                yPosOfWm = 10;
                break ;
            case ImagePosition .RigthBottom :
                xPosOfWm = phWidth - wmWidth - 10;
                yPosOfWm = phHeight - wmHeight - 10;
                break ;
            case ImagePosition.TopMiddle :
                xPosOfWm = (phWidth - wmWidth) / 2;
                yPosOfWm = 10;
                break ;
            default:
                xPosOfWm = 10;
                yPosOfWm = phHeight - wmHeight - 10;
                break;
        }

        //
        // 第二次绘图,把水印印上去
        //
        grWatermark.DrawImage(imgWatermark,
         new Rectangle(xPosOfWm,
                             yPosOfWm,
                             wmWidth,
                             wmHeight), 
                             0,              
                             0,          
                             wmWidth,  
                             wmHeight,   
                             GraphicsUnit.Pixel,  
                             imageAttributes);

       
        imgPhoto = bmWatermark;
        grPhoto.Dispose();
        grWatermark.Dispose();

        //
        // 保存文件到服务器的文件夹里面
        //
        imgPhoto.Save(targetImage, ImageFormat.Jpeg);
        imgPhoto.Dispose();
        imgWatermark.Dispose();
        return targetImage.Replace (PicturePath,"");
    }

    /// <summary>
    /// 在图片上添加水印文字
    /// </summary>
    /// <param name="sourcePicture">源图片文件</param>
    /// <param name="waterWords">需要添加到图片上的文字</param>
    /// <param name="alpha">透明度</param>
    /// <param name="position">位置</param>
    /// <param name="PicturePath">文件路径</param>
    /// <returns></returns>
    public string DrawWords(string sourcePicture,
                                      string waterWords,
                                      float alpha,
                                      ImagePosition position,
                                      string PicturePath)
    {
        //
        // 判断参数是否有效
        //
        if (sourcePicture == string.Empty || waterWords == string.Empty || alpha == 0.0 || PicturePath == string.Empty)
        {
            return sourcePicture;
        }

        //
        // 源图片全路径
        //
        string sourcePictureName = PicturePath + sourcePicture;
        string fileExtension = System.IO.Path.GetExtension(sourcePictureName).ToLower();

        //
        // 判断文件是否存在,以及文件名是否正确
        //
        if (System.IO.File.Exists(sourcePictureName) == false || (
            fileExtension != ".gif"  &&
            fileExtension != ".jpg" &&
            fileExtension != ".png" ))
        {
            return sourcePicture;
        }

        //
        // 目标图片名称及全路径
        //
        string targetImage = sourcePictureName.Replace(System.IO.Path.GetExtension(sourcePictureName), "") + "_0703.jpg";

        //创建一个图片对象用来装载要被添加水印的图片
        Image imgPhoto = Image.FromFile(sourcePictureName);

        //获取图片的宽和高
        int phWidth = imgPhoto.Width;
        int phHeight = imgPhoto.Height;

        //
        //建立一个bitmap,和我们需要加水印的图片一样大小
        Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);

        //SetResolution:设置此 Bitmap 的分辨率
        //这里直接将我们需要添加水印的图片的分辨率赋给了bitmap
        bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

        //Graphics:封装一个 GDI+ 绘图图面。
        Graphics grPhoto = Graphics.FromImage(bmPhoto);

        //设置图形的品质
        grPhoto.SmoothingMode = SmoothingMode.AntiAlias;

        //将我们要添加水印的图片按照原始大小描绘(复制)到图形中
        grPhoto.DrawImage(
         imgPhoto,                                           //   要添加水印的图片
         new Rectangle(0, 0, phWidth, phHeight), //  根据要添加的水印图片的宽和高
         0,                                                     //  X方向从0点开始描绘
         0,                                                     // Y方向 
         phWidth,                                            //  X方向描绘长度
         phHeight,                                           //  Y方向描绘长度
         GraphicsUnit.Pixel);                              // 描绘的单位,这里用的是像素

        //根据图片的大小我们来确定添加上去的文字的大小
        //在这里我们定义一个数组来确定
        int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 };

        //字体
        Font crFont = null;
        //矩形的宽度和高度,SizeF有三个属性,分别为Height高,width宽,IsEmpty是否为空
        SizeF crSize = new SizeF();

        //利用一个循环语句来选择我们要添加文字的型号
        //直到它的长度比图片的宽度小
        for (int i = 0; i < 7; i++)
        {
            crFont = new Font("arial", sizes[i], FontStyle.Bold);

            //测量用指定的 Font 对象绘制并用指定的 StringFormat 对象格式化的指定字符串。
            crSize = grPhoto.MeasureString(waterWords, crFont);

            // ushort 关键字表示一种整数数据类型
            if ((ushort)crSize.Width < (ushort)phWidth)
                break;
        }

        //截边5%的距离,定义文字显示(由于不同的图片显示的高和宽不同,所以按百分比截取)
        int yPixlesFromBottom = (int)(phHeight * .05);

        //定义在图片上文字的位置
        float wmHeight =  crSize.Height;
        float wmWidth = crSize .Width ;

        float  xPosOfWm;
        float  yPosOfWm;

        switch (position)
        {
            case ImagePosition .BottomMiddle :
                xPosOfWm = phWidth / 2 ;
                yPosOfWm = phHeight- wmHeight -10;
                break ;
            case ImagePosition .Center :
                xPosOfWm = phWidth / 2;
                yPosOfWm = phHeight / 2;
                break ;
            case ImagePosition .LeftBottom :
                xPosOfWm = wmWidth;
                yPosOfWm = phHeight - wmHeight - 10;
                break ;
            case ImagePosition .LeftTop :
                xPosOfWm = wmWidth/2 ;
                yPosOfWm = wmHeight / 2;
                break;
            case ImagePosition .RightTop :
                xPosOfWm = phWidth - wmWidth - 10;
                yPosOfWm = wmHeight;
                break ;
            case ImagePosition .RigthBottom :
                xPosOfWm = phWidth - wmWidth - 10;
                yPosOfWm = phHeight - wmHeight - 10;
                break ;
            case ImagePosition.TopMiddle :
                xPosOfWm = phWidth / 2;
                yPosOfWm = wmWidth;
                break ;
            default:
                xPosOfWm = wmWidth;
                yPosOfWm = phHeight - wmHeight - 10;
                break;
        }

        //封装文本布局信息(如对齐、文字方向和 Tab 停靠位),显示操作(如省略号插入和国家标准 (National) 数字替换)和 OpenType 功能。
        StringFormat StrFormat = new StringFormat();

        //定义需要印的文字居中对齐
        StrFormat.Alignment = StringAlignment.Center;

        //SolidBrush:定义单色画笔。画笔用于填充图形形状,如矩形、椭圆、扇形、多边形和封闭路径。
        //这个画笔为描绘阴影的画笔,呈灰色
        int m_alpha = Convert .ToInt32 ( 256 * alpha);
        SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(m_alpha, 0, 0, 0));

        //描绘文字信息,这个图层向右和向下偏移一个像素,表示阴影效果
        //DrawString 在指定矩形并且用指定的 Brush 和 Font 对象绘制指定的文本字符串。
        grPhoto.DrawString(waterWords,                                    //string of text
                                   crFont,                                         //font
                                   semiTransBrush2,                            //Brush
                                   new PointF(xPosOfWm + 1, yPosOfWm + 1),  //Position
                                   StrFormat);

        //从四个 ARGB 分量(alpha、红色、绿色和蓝色)值创建 Color 结构,这里设置透明度为153
        //这个画笔为描绘正式文字的笔刷,呈白色
        SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));

        //第二次绘制这个图形,建立在第一次描绘的基础上
        grPhoto.DrawString(waterWords,                 //string of text
                                   crFont,                                   //font
                                   semiTransBrush,                           //Brush
                                   new PointF(xPosOfWm, yPosOfWm),  //Position
                                   StrFormat);

        //imgPhoto是我们建立的用来装载最终图形的Image对象
        //bmPhoto是我们用来制作图形的容器,为Bitmap对象
        imgPhoto = bmPhoto;
        //释放资源,将定义的Graphics实例grPhoto释放,grPhoto功德圆满
        grPhoto.Dispose();

        //将grPhoto保存
        imgPhoto.Save(targetImage, ImageFormat.Jpeg);
        imgPhoto.Dispose();

        return targetImage.Replace(PicturePath, "");
    }
}

/// <summary>
/// 装载水印图片的相关信息
/// </summary>
public class WaterImage
{
    public WaterImage ()
    {

    }

    private string m_sourcePicture;
    /// <summary>
    /// 源图片地址名字(带后缀)
    /// </summary>
    public string SourcePicture
    {
        get { return m_sourcePicture; }
        set { m_sourcePicture = value; }
    }

    private string  m_waterImager;
    /// <summary>
    /// 水印图片名字(带后缀)
    /// </summary>
    public string  WaterPicture
    {
        get { return m_waterImager; }
        set { m_waterImager = value; }
    }

    private float  m_alpha;
    /// <summary>
    /// 水印图片文字的透明度
    /// </summary>
    public float  Alpha
    {
        get { return m_alpha; }
        set { m_alpha = value; }
    }

    private ImagePosition  m_postition;
    /// <summary>
    /// 水印图片或文字在图片中的位置
    /// </summary>
    public ImagePosition  Position
    {
        get { return m_postition; }
        set { m_postition = value; }
    }

    private string  m_words;
    /// <summary>
    /// 水印文字的内容
    /// </summary>
    public string  Words
    {
        get { return m_words; }
        set { m_words = value; }
    }
  
}
 

三、 图片+水印(透明)函数

<summary>   
   /// 添加图片水印   
   /// </summary>   
   /// <param name="path">原图片绝对地址</param>   
   /// <param name="Ext">文件后缀</param>   
   public static string addWaterMark(string path,string fileExt)   
   {   
    System.Drawing.Image image = System.Drawing.Image.FromFile(path);   
    Bitmap b = new Bitmap(image.Width, image.Height,System.Drawing.Imaging.PixelFormat.Format24bppRgb);   
    Graphics g = Graphics.FromImage(b);   
    g.Clear(Color.White);   
    g.DrawImage(image, 0, 0, image.Width, image.Height);   
  
    Image watermark = new Bitmap(ConfigurationSettings.AppSettings["PersonalPath"] + @"images\logo.jpg");   
  
    System.Drawing.Imaging.ImageAttributes imageAttributes = new System.Drawing.Imaging.ImageAttributes();   
    System.Drawing.Imaging.ColorMap colorMap = new System.Drawing.Imaging.ColorMap();   
    colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);   
    colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);   
    System.Drawing.Imaging.ColorMap[] remapTable = {colorMap};   
    imageAttributes.SetRemapTable(remapTable, System.Drawing.Imaging.ColorAdjustType.Bitmap);   
    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, 0.3f, 0.0f},   
             new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}   
            };   
    System.Drawing.Imaging.ColorMatrix colorMatrix = new System.Drawing.Imaging.ColorMatrix(colorMatrixElements);   
    imageAttributes.SetColorMatrix(colorMatrix, System.Drawing.Imaging.ColorMatrixFlag.Default, System.Drawing.Imaging.ColorAdjustType.Bitmap);   
    int xpos = 0;   
    int ypos = 0;   
      
    xpos = ((image.Width - watermark.Width) - 10);   
    ypos = image.Height - watermark.Height - 10;   
  
    g.DrawImage(watermark, new Rectangle(xpos, ypos, watermark.Width, watermark.Height), 0, 0, watermark.Width, watermark.Height, GraphicsUnit.Pixel, imageAttributes);   
  
    watermark.Dispose();   
    imageAttributes.Dispose();   
  
  
    //保存加水印过后的图片,删除原始图片   
    Random ro=new Random((int)DateTime.Now.Ticks);   
    string temppath = System.DateTime.Now.ToString("yyyy") + "\\" + System.DateTime.Now.ToString("MMdd");   
    string fileName = temppath + "\\" + DateTime.Now.ToString("yyyyMMddHHmmss") + ro.Next(10000) + fileExt;   
    string filepath = Functions.GetUserFactPath(User.GetUserFromSession().Adddate,User.GetUserFromSession().UserId) + "3\\";   
      
  
    b.Save(filepath + fileName);   
    b.Dispose();   
    image.Dispose();   
    if(File.Exists(path))   
    {   
     File.Delete(path);   
    }   
  
    return fileName;   
   }

原文地址:https://www.cnblogs.com/Yjianyong/p/2742964.html