自己做了一个PDF说明文件给客户，现在需要在每一页上都加上自己的logo图片，具体操作过程如下：

建项目这些就省略了，直接上代码：

using iTextSharp.text.pdf;
using System;
using System.IO;
using System.Windows.Forms;

namespace Pic2PDF
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string path = Application.StartupPath;

            //源PDF地址
            string pdffilename = path + "test.pdf";
            //加完图片的PDF地址
            string pdffilename1 = path + "test1.pdf";
            //图片文件地址
            string picfilename = path + "sign.jpg";

            //执行操作,加上图片
            string r = AddPics(pdffilename, pdffilename1, picfilename);
            MessageBox.Show(r);
        }
        public static string AddPics(string PdfPath, string OutPdfPath, string picpath)
        {
            try
            {
                if (File.Exists(OutPdfPath))
                {
                    File.Delete(OutPdfPath);
                }
                PdfReader reader = new PdfReader(PdfPath);
                PdfStamper stamp = new PdfStamper(reader, new FileStream(OutPdfPath, FileMode.Create));
                int n = reader.NumberOfPages;
                int i = 0;
                PdfContentByte under;
                iTextSharp.text.Image im = iTextSharp.text.Image.GetInstance(picpath);

                PDFATT att = new PDFATT(PdfPath);
                float ww = att.Width();
                float hh = att.Height();

                float w = im.Width;
                float h = im.Height;
 
                float locationx;
                float locationy;

                locationx = ww - w - 20;
                locationy = 50;

                im.SetAbsolutePosition(locationx, locationy);
                im.ScaleAbsolute(w, h);

                while (i < n)
                {
                    i++;
                    under = stamp.GetOverContent(i);
                    under.AddImage(im, false);
                }
                stamp.Close();
                reader.Close();
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
            return "ok";
        }
        class PDFATT
        {
            PdfReader reader;
            public PDFATT(string iPdfFilePath)
            {
                reader = new PdfReader(iPdfFilePath);
            }
            public int PageCount()
            {
                return reader.NumberOfPages;
            }
            public float Width()
            {
                return reader.GetPageSize(1).Width;
            }
            public float Height()
            {
                return reader.GetPageSize(1).Height;
            }
        }
    }
}

我这里设置的是添加到右下角了，位置的代码主要在这个地方

PDFATT att = new PDFATT(PdfPath);

float ww = att.Width(); //PDF的宽度

float hh = att.Height(); //PDF的高度

float w = im.Width; //图片宽

float h = im.Height; //图片高

float locationx;

float locationy;

locationx = ww - w - 20; //横向位置自己计算

locationy = 50; //纵向位置自己试下就行

其它的都很简单了。

运行效果如下：