C# 图片转PDF，PDF增加水印文字

　　好久没写博客了，今天给大家分享一个图片转PDF的相关操作，也算是一次总结吧。

　　首先需要准备动态库itextsharp.dll，这个dll去网上下载，都可以下载到，C#对PDF的操作都是基于这个类库来实现的。话不多说，直接上代码。

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/// /// 导出PDF /// /// 图片的路劲 /// 图片的名称 private bool PrintToPdf(string FilePath,string FileName ) {                 iTextSharp.text.Rectangle rec = new iTextSharp.text.Rectangle(0, 0, iTextSharp.text.PageSize.A4.Width, iTextSharp.text.PageSize.A4.Height);     iTextSharp.text.Image image;     iTextSharp.text.Document document = null;     FileStream fs = null;     PdfWriter writer = null;     try     {         //生成PDF         document = new iTextSharp.text.Document(rec);         fs = new FileStream(FilePath + FileName + ".pdf", FileMode.Create);           PdfWriter.GetInstance(document, fs);         document.Open();         image = iTextSharp.text.Image.GetInstance(FilePath + FileName + ".jpg");         //调整图片大小，使之适合A4         if (image.Height > rec.Height)         {             image.ScaleToFit(rec.Width, rec.Height);         }         else if (image.Width > rec.Width)         {             image.ScaleToFit(rec.Width, rec.Height);         }           //调整图片位置，使之居中         image.Alignment = iTextSharp.text.Image.ALIGN_MIDDLE;         document.NewPage();         document.Add(image);     }     catch (Exception ex)     {         return false;     }     finally     {         if (document.IsOpen())         {             document.Close();         }         fs.Close();           //最后删除生成的图片         File.Delete(FilePath + FileName + ".jpg");     }       try     {         //添加水印图片，水印图片采取的是先生成图片，再添加到PDF文件中         document = new iTextSharp.text.Document(rec);         fs = new FileStream(FilePath + FileName + ".pdf", FileMode.Open);         writer = PdfWriter.GetInstance(document, fs);         iTextSharp.text.Image imgWater = CreateWaterImage();         PdfReader reader = new PdfReader(fs);         document.Open();         PdfContentByte cb = writer.DirectContent;         PdfImportedPage newPage;         int iPageNum = reader.NumberOfPages;         for (int j = 1; j <= iPageNum; j++)         {             document.NewPage();             newPage = writer.GetImportedPage(reader, j);               //pdf旋转             if (newPage.Width > newPage.Height)             {                 cb.AddTemplate(newPage, 0, -1f, 1f, 0, 0, newPage.Width);             }             else             {                 cb.AddTemplate(newPage, 0, 0);             }             cb.AddImage(imgWater);         }         return true;     }     catch (Exception ex)     {         return false;     }     finally     {         if (document.IsOpen())         {             document.Close();         }         writer.Close();         fs.Close();     } }   /// /// 生成水印图片 /// /// private iTextSharp.text.Image CreateWaterImage() {     string WaterText = "水印文本";     Bitmap bitmap = new Bitmap(595, 842);     using (Graphics g = Graphics.FromImage(bitmap))     {         //重置图像         g.ResetTransform();         //设置旋转中心         g.TranslateTransform(bitmap.Width / 2, bitmap.Height / 2);         //旋转50度 顺时针         g.RotateTransform(-50);         //指定文本呈现的质量 解决文字锯齿问题         g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;         System.Drawing.Font font = new System.Drawing.Font("微软雅黑", 14);         SolidBrush solidBrush = new SolidBrush(Color.FromArgb(100, 0, 0, 0));           //设置文字、字体、大小、颜色、起始位置         g.DrawString(WaterText, font, solidBrush, new Point(-240, -100));           g.DrawString(WaterText, font, solidBrush, new Point(-340, 100));     }           //把水印图片保存在系统指定位置     bitmap.Save("C:\\WaterTemp.jpg");       iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance("C:\\WaterTemp.jpg");     //透明度，灰色填充     image.GrayFill = 20;     image.SetAbsolutePosition(0, 0);       return image; }