[置顶] ASP.NET图片加水印的实现代码

# using System; # using System.Collections.Generic; # using System.Text; # # using System.IO; # using System.Drawing; # using System.Drawing.Imaging; # using System.Drawing.Drawing2D; # # namespace DocMIS.AppConfig # { # /**//// < summary> # /// 水印位置 # /// < /summary> # public enum ImagePosition # { # /**//// < summary> # /// 左上 # /// < /summary> # LeftTop, # /**//// < summary> # /// 左下 # /// < /summary> # LeftBottom, # /**//// < summary> # /// 右上 # /// < /summary> # RightTop, # /**//// < summary> # /// 右下 # /// < /summary> # RigthBottom, # /**//// < summary> # /// 顶部居中 # /// < /summary> # TopMiddle, # /**//// < summary> # /// 底部居中 # /// < /summary> # BottomMiddle, # /**//// < summary> # /// 中心 # /// < /summary> # Center # } # # /**//// < summary> # /// 图像操作类(主要用于给图片加上透明文字水印) # /// < /summary> # class ImageWater_Word # { # private string _ErrMsg; # #region 出错信息 # /**//// < summary> # /// 出错信息 # /// < /summary> # public string ErrMsg # { # get { return _ErrMsg; } # set { _ErrMsg = value; } # } # #endregion # # # #region 将文件转换成流 # //public byte[] SetImageToByteArray(string fileName, ref string fileSize) # /**//// < summary> # /// 将文件转换成流 # /// < /summary> # /// < param name="fileName">文件全路径< /param> # /// < returns>< /returns> # private byte[] SetImageToByteArray(string fileName) # { # byte[] image = null; # try # { # FileStream fs = new FileStream(fileName, FileMode.Open); # FileInfo fileInfo = new FileInfo(fileName); # //fileSize = Convert.ToDecimal(fileInfo.Length / 1024).ToString("f2") + " K"; # int streamLength = (int)fs.Length; # image = new byte[streamLength]; # fs.Read(image, 0, streamLength); # fs.Close(); # return image; # } # catch # { # return image; # } # } # #endregion # # #region 将byte转换成MemoryStream类型 # /**//// < summary> # /// ASP.NET图片加水印：将byte转换成MemoryStream类型 # /// < /summary> # /// < param name="mybyte">byte[]变量< /param> # /// < returns>< /returns> # private MemoryStream ByteToStream(byte[] mybyte) # { # MemoryStream mymemorystream = new MemoryStream(mybyte, 0, mybyte.Length); # return mymemorystream; # } # #endregion # # #region 将byte转换成Image文件 # /**//// < summary> # /// ASP.NET图片加水印：将byte转换成Image文件 # /// < /summary> # /// < param name="mybyte">byte[]变量< /param> # /// < returns>< /returns> # private System.Drawing.Image SetByteToImage(byte[] mybyte) # { # System.Drawing.Image image; # MemoryStream mymemorystream = new MemoryStream(mybyte, 0, mybyte.Length); # image = System.Drawing.Image.FromStream(mymemorystream); # return image; # } # #endregion # # # #region 批量在图片上添加透明水印文字 # /**//// < summary> # /// ASP.NET图片加水印：批量在图片上添加透明水印文字 # /// < /summary> # /// < param name="arrsourcePicture">原来图片地址(路径+文件名)< /param> # /// < param name="waterWords">需要添加到图片上的文字< /param> # /// < param name="alpha">透明度(0.1~1.0之间)< /param> # /// < param name="position">文字显示的位置< /param> # /// < param name="fRewrite">是否覆盖原图片(如果不覆盖，那么将在同目录下生成一个文件名带0607的文件)< /param> # /// < returns>< /returns> # public bool DrawWords(string[] arrsourcePicture, string waterWords, float alpha, ImagePosition position, bool fRewrite) # { # foreach (string imgPath in arrsourcePicture) # { # if (!DrawWords(imgPath, waterWords, alpha, position, fRewrite)) # { # _ErrMsg += "——处理文件：" + imgPath + " 时出错。"; # return false; # } # } # return true; # } # #endregion # # #region 在图片上添加透明水印文字 # /**//// < summary> # /// ASP.NET图片加水印：在图片上添加透明水印文字 # /// < /summary> # /// < param name="sourcePicture">原来图片地址(路径+文件名)< /param> # /// < param name="waterWords">需要添加到图片上的文字< /param> # /// < param name="alpha">透明度(0.1~1.0之间)< /param> # /// < param name="position">文字显示的位置< /param> # /// < param name="fRewrite">是否覆盖原图片(如果不覆盖，那么将在同目录下生成一个文件名带0607的文件)< /param> # /// < returns>< /returns> # public bool DrawWords(string sourcePicture, string waterWords, float alpha, ImagePosition position, bool fRewrite) # { # if (!System.IO.File.Exists(sourcePicture)) # { # _ErrMsg = "文件不存在！"; # return false; # } # string fileExtension = System.IO.Path.GetExtension(sourcePicture).ToLower(); # if (fileExtension != ".gif" && fileExtension != ".jpg" && fileExtension != ".png" && fileExtension != ".bmp") # { # _ErrMsg = "不是图片文件！"; # return false; # } # # Image imgPhoto = null; # Bitmap bmPhoto = null; # Graphics grPhoto = null; # try # { # //创建一个图片对象用来装载要被添加水印的图片 # imgPhoto = Image.FromStream(ByteToStream(SetImageToByteArray(sourcePicture))); # # //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 # 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。 # 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[] { 48, 36, 28, 24, 16, 14, 12, 10 }; # # //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 < sizes.Length; 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; # # //设置水印的位置 # 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 # if (fRewrite) # { # imgPhoto.Save(sourcePicture); # } # else # { # // 目标图片名称及全路径 # string targetImage = sourcePicture.Replace(System.IO.Path.GetExtension(sourcePicture), "") + "_0607" + fileExtension; # imgPhoto.Save(targetImage); # } # //imgPhoto.Dispose(); # return true; # } # catch (Exception ex) # { # _ErrMsg = ex.Message; # return false; # } # finally # { # if (imgPhoto != null) # imgPhoto.Dispose(); # if (bmPhoto != null) # bmPhoto.Dispose(); # if (grPhoto != null) # grPhoto.Dispose(); # } # # # } # #endregion # # } # }