使用C#代码在现有 PDF 文档中添加页眉

PM> Install-Package Spire.PDF

using Spire.Pdf;
using Spire.Pdf.AutomaticFields;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace AddHeaderToExistingPdf
{ 
    class Program
    {
        static void Main(string[] args)
        {
            //创建 PdfDocument 对象
            PdfDocument doc = new PdfDocument();

            //加载 PDF 文件
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\TargetMarket.pdf");

            //加载用于页眉的图片
            PdfImage headerImage = PdfImage.FromFile("C:\\Users\\Administrator\\Desktop\\logo.png");

            //获取图片宽度（像素）
            float width = headerImage.Width;

            //将像素转换为点
            PdfUnitConvertor unitCvtr = new PdfUnitConvertor();
            float pointWidth = unitCvtr.ConvertUnits(width, PdfGraphicsUnit.Pixel, PdfGraphicsUnit.Point);

            //指定页眉文本
            string headerText = "E-iceblue Tech\nwww.e-iceblue.com";

            //创建 TrueType 字体
            PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Times New Roman", 12f, FontStyle.Bold), true);

            //创建画刷
            PdfBrush brush = PdfBrushes.Purple;

            //创建画笔
            PdfPen pen = new PdfPen(brush, 1.0f);

            //创建文档创建日期字段
            PdfCreationDateField creationDateField = new PdfCreationDateField(font, brush);
            creationDateField.DateFormatString = "yyyy-MM-dd";

            //创建复合字段，将静态文本与日期字段组合在一起
            PdfCompositeField compositeField = new PdfCompositeField(font, brush, "creation time: {0}", creationDateField);
            compositeField.Location = new Point(55, 48);

            //遍历文档中的所有页面
            for (int i = 0; i < doc.Pages.Count; i++)
            {
                //获取当前页面
                PdfPageBase page = doc.Pages[i];

                //在顶部空白区域绘制图片
                page.Canvas.DrawImage(headerImage, page.ActualSize.Width - pointWidth - 55, 20);

                //在顶部空白区域绘制文本
                page.Canvas.DrawString(headerText, font, brush, 55, 20);

                //在顶部空白区域绘制分隔线
                page.Canvas.DrawLine(pen, new PointF(55, 70), new PointF(page.ActualSize.Width - 55, 70));

                //在顶部空白区域绘制复合字段
                compositeField.Draw(page.Canvas);
            }

            //保存文件
            doc.SaveToFile("AddHeader.pdf");
            doc.Dispose();
        }
    }
}