最近在做关于PDF文档添加水印的功能，折腾了好久，终于好了。以下做个记录：
首先会用到iTextSharp组件，大家可以去官网下载，同时我也会在本文中附加进来。
代码中添加引用为：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using iTextSharp.text.pdf;
using System.IO;
using iTextSharp.text;
创建一个显示指定图片的pdf
/// <summary>
/// 创建一个显示指定图片的pdf
/// </summary>
/// <param name="picPdfPath"></param>
/// <param name="picPath"></param>
/// <returns></returns>
public static bool CreatePDFByPicstring picPdfPath,string picPath)
{
//新建一个文档
Document doc = new Document);
try
{
//建立一个书写器Writer)与document对象关联
PdfWriter.GetInstancedoc, new FileStreampicPdfPath, FileMode.Create, FileAccess.ReadWrite));
//打开一个文档
doc.Open);
//向文档中添加内容
Image img = Image.GetInstancepicPath);
//img.SetAbsolutePosition);
doc.Addimg);
return true;
}
catch Exception ex)
{
return false;
throw ex;
}
finally
{
if doc != null)
{
doc.Close);
}
}
}
为PDF文档添加图片水印
/// <summary>
/// 加图片水印
/// </summary>
/// <param name="inputfilepath"></param>
/// <param name="outputfilepath"></param>
/// <param name="ModelPicName"></param>
/// <param name="top"></param>
/// <param name="left"></param>
/// <returns></returns>
public static bool PDFWatermarkstring inputfilepath, string outputfilepath, string ModelPicName, float top, float left)
{
//throw new NotImplementedException);
PdfReader pdfReader = null;
PdfStamper pdfStamper = null;
try
{
pdfReader = new PdfReaderinputfilepath);
int numberOfPages = pdfReader.NumberOfPages;
iTextSharp.text.Rectangle psize = pdfReader.GetPageSize1);
float width = psize.Width;
float height = psize.Height;
pdfStamper = new PdfStamperpdfReader, new FileStreamoutputfilepath, FileMode.Create));
PdfContentByte waterMarkContent;
iTextSharp.text.Image image = iTextSharp.text.Image.GetInstanceModelPicName);
image.GrayFill = 20;//透明度，灰色填充
//image.Rotation//旋转
//image.RotationDegrees//旋转角度
//水印的位置
if left < 0)
{
left = width/2 - image.Width + left;
}
//image.SetAbsolutePositionleft, height - image.Height) - top);
image.SetAbsolutePositionleft, height/2 - image.Height) - top);
//每一页加水印,也可以设置某一页加水印
for int i = 1; i <= numberOfPages; i++)
{
//waterMarkContent = pdfStamper.GetUnderContenti);//内容下层加水印
waterMarkContent = pdfStamper.GetOverContenti);//内容上层加水印
waterMarkContent.AddImageimage);
}
//strMsg = "success";
return true;
}
catch Exception ex)
{
throw ex;
}
finally
{
if pdfStamper != null)
pdfStamper.Close);
if pdfReader != null)
pdfReader.Close);
}
}
添加普通偏转角度文字水印
/// <summary>
/// 添加普通偏转角度文字水印
/// </summary>
/// <param name="inputfilepath"></param>
/// <param name="outputfilepath"></param>
/// <param name="waterMarkName"></param>
/// <param name="permission"></param>
public static void setWatermarkstring inputfilepath, string outputfilepath,string waterMarkName)
{
PdfReader pdfReader = null;
PdfStamper pdfStamper = null;
//获取所用权
PdfReader.unethicalreading = true;
try
{
pdfReader = new PdfReaderinputfilepath);
pdfStamper = new PdfStamperpdfReader, new FileStreamoutputfilepath, FileMode.Create));
int total = pdfReader.NumberOfPages + 1;
iTextSharp.text.Rectangle psize = pdfReader.GetPageSize1);
float width = psize.Width;
float height = psize.Height;
PdfContentByte content;
BaseFont font = BaseFont.CreateFont@"C:WINDOWSFontsSIMFANG.TTF", BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
PdfGState gs = new PdfGState);
for int i = 1; i < total; i++)
{
content = pdfStamper.GetOverContenti);//在内容上方加水印
//content = pdfStamper.GetUnderContenti);//在内容下方加水印
//透明度
gs.FillOpacity = 0.3f;
content.SetGStategs);
//content.SetGrayFill0.3f);
//开始写入文本
content.BeginText);
content.SetColorFillBaseColor.LIGHT_GRAY);
content.SetFontAndSizefont, 100);
content.SetTextMatrix0, 0);
content.ShowTextAlignedElement.ALIGN_CENTER, waterMarkName, width / 2 - 50,height / 2 - 50, 55);
//content.SetColorFillBaseColor.BLACK);
//content.SetFontAndSizefont, 8);
//content.ShowTextAlignedElement.ALIGN_CENTER, waterMarkName, 0, 0, 0);
content.EndText);
}
}catch Exception ex)
{
throw ex;
}
finally
{
if pdfStamper != null)
pdfStamper.Close);
if pdfReader != null)
pdfReader.Close);
}
}
添加倾斜水印
/// <summary>
/// 添加倾斜水印
/// </summary>
/// <param name="inputfilepath"></param>
/// <param name="outputfilepath"></param>
/// <param name="waterMarkName"></param>
/// <param name="userPassWord"></param>
/// <param name="ownerPassWord"></param>
/// <param name="permission"></param>
public static void setWatermarkstring inputfilepath, string outputfilepath, string waterMarkName, string userPassWord, string ownerPassWord, int permission)
{
PdfReader pdfReader = null;
PdfStamper pdfStamper = null;
try
{
pdfReader = new PdfReaderinputfilepath);
pdfStamper = new PdfStamperpdfReader, new FileStreamoutputfilepath, FileMode.Create));
// 设置密码
//pdfStamper.SetEncryptionfalse,userPassWord, ownerPassWord, permission);
int total = pdfReader.NumberOfPages + 1;
PdfContentByte content;
BaseFont font = BaseFont.CreateFont@"C:WINDOWSFontsSIMFANG.TTF", BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
PdfGState gs = new PdfGState);
gs.FillOpacity = 0.2f;//透明度
int j = waterMarkName.Length;
char c;
int rise = 0;
for int i = 1; i < total; i++)
{
rise = 500;
content = pdfStamper.GetOverContenti);//在内容上方加水印
//content = pdfStamper.GetUnderContenti);//在内容下方加水印
content.BeginText);
content.SetColorFillBaseColor.DARK_GRAY);
content.SetFontAndSizefont, 50);
// 设置水印文字字体倾斜 开始
if j >= 15)
{
content.SetTextMatrix200, 120);
for int k = 0; k < j; k++)
{
content.SetTextRiserise);
c = waterMarkName[k];
content.ShowTextc + "");
rise -= 20;
}
}
else
{
content.SetTextMatrix180, 100);
for int k = 0; k < j; k++)
{
content.SetTextRiserise);
c = waterMarkName[k];
content.ShowTextc + "");
rise -= 18;
}
}
// 字体设置结束
content.EndText);
// 画一个圆
//content.Ellipse250, 450, 350, 550);
//content.SetLineWidth1f);
//content.Stroke);
}
}
catch Exception ex)
{
throw ex;
}
finally
{
if pdfStamper != null)
pdfStamper.Close);
if pdfReader != null)
pdfReader.Close);
}
}
调用方法的例子：
string path = "D://my.pdf";
HtmlToPDFUtil.HtmlToPdfRequest.Url.AbsoluteUri, path);
//HtmlToPDFUtil.HtmlToPdfsbUrlList.ToString), path);
PDFSetWaterMark.PDFWatermarkpath, "D://my.pdf", Server.MapPath"/HtmlToPdf/Tools/sy.bmp"), 0, 0);
PDFSetWaterMark.setWatermark"D://my.pdf", "D://my2.pdf", "TEST");
//PDFSetWaterMark.setWatermark"D://my.pdf", "D://my2.pdf", "TEST", "", "", 1);