用pdfsharp写一段删除PDF文档中直线的代码

以下是使用pdfsharp删除PDF文档中直线的示例代码：

using PdfSharp.Pdf;
using PdfSharp.Pdf.Content;
using PdfSharp.Pdf.Content.Objects;
using PdfSharp.Pdf.IO;
using PdfSharp.Pdf.AcroForms;
using PdfSharp.Drawing;

public static void RemoveLines(string inputFilePath, string outputFilePath)
{
    // Load the PDF document
    PdfDocument document = PdfReader.Open(inputFilePath, PdfDocumentOpenMode.Modify);

    // Loop through all pages of the PDF document
    foreach (PdfPage page in document.Pages)
    {
        // Get the content of the page
        CObject content = ContentReader.ReadContent(page);

        // Loop through all content elements of the page
        for (int i = content.Elements.Count - 1; i >= 0; i--)
        {
            COperator op = content.Elements[i] as COperator;

            // Check if the content element is a line
            if (op != null && op.OpCode.Name == "l")
            {
                // Remove the line from the content
                content.Elements.RemoveAt(i);
            }
        }

        // Replace the content of the page with the modified content
        page.Contents.Clear();
        page.Contents.Add(content);
    }

    // Save the modified PDF document
    document.Save(outputFilePath);
    document.Close();
}

此代码加载PDF文档，循环遍历所有页面，获取页面内容，然后查找并删除所有直线元素，最后将修改后的内容替换回页面并保存PDF文档。