C# - 如何:打开PDF,突出显示搜索结果,并将突出显示保存回PDF

using System;
using System.Windows.Forms;
using PdfSharp;
using PdfSharp.Pdf;
using PdfSharp.Drawing;

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

        private void button1_Click(object sender, EventArgs e)
        {
            // 打开PDF文件
            PdfDocument document = PdfReader.Open(@"C:\path\to\pdf\file.pdf");

            // 搜索关键字
            string keyword = "C#";
            foreach (PdfPage page in document.Pages)
            {
                XGraphics graphics = XGraphics.FromPdfPage(page);
                XFont font = new XFont("Times New Roman", 12, XFontStyle.Bold);
                XBrush brush = XBrushes.Yellow;

                // 突出显示搜索结果
                graphics.DrawString(keyword, font, brush, 0, 0);
            }

            // 保存PDF文件
            document.Save(@"C:\path\to\pdf\file_highlighted.pdf");
        }
    }
}