Document doc = new Document();
            doc.LoadFromFile("in.epub", Spire.Doc.FileFormat.EPub);
            doc.SaveToFile(@"out.docx", Spire.Doc.FileFormat.Docx);
            doc.SaveToFile(@"out.pdf", Spire.Doc.FileFormat.PDF);

Document doc = new Document();
            doc.LoadFromFile("in.docx");
            ToPdfParameterList list = new ToPdfParameterList();
            list.PdfConformanceLevel = PdfConformanceLevel.Pdf_UA1;
            doc.SaveToFile(@"out.pdf", list);

Document doc = new Document();
Paragraph paragraph = doc.AddSection().AddParagraph();
Chart chart = paragraph.AppendChart(ChartType.Column, 450, 300).Chart;
//Modify 'Series 3' to a line chart and display it on the secondary axis
chart.ChangeSeriesType("Series 3", ChartSeriesType.Line, true);
Console.WriteLine(chart.Series[2].ChartType);
doc.SaveToFile("ComboChart.docx"); 

Document document = new Document();
//Set default replacement font
doc.DefaultSubstitutionFontName = "Arial";
Section sec = doc.AddSection();
Paragraph para = sec.AddParagraph();
TextRange tr = para.AppendText("test");
//The system does not have this font
tr.CharacterFormat.FontName = "Helvetica";
doc.SaveToFile(outputFile, FileFormat.PDF);
doc.Close(); 

// Process inline structure tags
            List tagInlines = structureTags.getM_tagInlines();
            for (int i = 0; i < tagInlines.Count; i++)
            {
                tagInlines[i].RemoveSelfOnly();
            }

            // Process other structure tags
            List tags = structureTags.getM_tags();
            for (int i = 0; i < tags.Count; i++)
            {
                tags[i].RemoveSelfOnly();
            }

            // Process StructureDocumentTagRow
            List rowtags = structureTags.getM_rowtags();
            for (int i = 0; i < rowtags.Count; i++)
            {
                rowtags[i].RemoveSelfOnly();
            }

            // Process StructureDocumentTagCell
            List celltags = structureTags.getM_celltags();
            for (int i = 0; i < celltags.Count; i++)
            {
                celltags[i].RemoveSelfOnly();
            } 

Document document = new Document();
 document.LoadFromFile(@"Sample.docx");
 ToPdfParameterList para = new ToPdfParameterList();
 para.PdfImageCompression = Spire.Doc.Export.PdfImageCompression.Jpeg;
 document.SaveToFile(outputFile,para); 

Document document = new Document();
            Section section = doc.AddSection();

            foreach (string ommlCode in OmmlCodes)
            {
                OfficeMath officeMath = new OfficeMath(doc);
                officeMath.CharacterFormat.FontSize = 14f;
                officeMath.FromOMMLCode(ommlCode);
                section.AddParagraph().ChildObjects.Add(officeMath);
            }

            doc.SaveToFile(outputFile, FileFormat.Docx2013);
            doc.Dispose(); 

Document document = new Document();
            doc.LoadFromFile(inputFile);

            StringBuilder stringBuilder = new StringBuilder();
            // Iterate through sections in the document
            foreach (Section section in doc.Sections)
            {
                // Iterate through paragraphs in each section
                foreach (Paragraph par in section.Body.Paragraphs)
                {
                    // Iterate through child objects in each paragraph
                    foreach (DocumentObject obj in par.ChildObjects)
                    {
                        // Check if the object is an OfficeMath equation
                        OfficeMath omath = obj as OfficeMath;
                        if (omath == null) continue;
                        // Convert OfficeMath equation to LaTex code
                        string mathml = omath.ToLaTexMathCode();
                        // Append MathML code to the StringBuilder
                        stringBuilder.Append("LaTeX code" + mathml);
                        stringBuilder.Append("\r\n");
                    }
                }
            }
            // Write the LaTex code to a text file
            File.WriteAllText(outputFile, stringBuilder.ToString())

PdfDocument doc = new PdfDocument(inputFile);    
PdfApplicationData appplicationDataObject = doc.GetCustomApplicationData();     
Dictionary privateDataObject = appplicationDataObject.Private as Dictionary;          
string privateData = privateDataObject["WinsertPrivateCatalogData"] as string;

PdfDocument doc = new PdfDocument();
doc.LoadFromFile("in.pdf");
XlsxLineLayoutOptions options = new XlsxLineLayoutOptions(false, false, false, true);
options.TextRecognizer = new TextRecognizer();
doc.ConvertOptions.SetPdfToXlsxOptions(options);
doc.SaveToFile("out.xlsx", Spire.Pdf.FileFormat.XLSX);
 
// niget install PaddleOCRSharp lib
using PaddleOCRSharp;
using Spire.Pdf.Conversion;

public class TextRecognizer : ITextRecognizer
{
    private static readonly PaddleOCREngine _engine;

    static TextRecognizer()
   

{         _engine = new PaddleOCREngine(null, “”);     }
    public string RecognizeGlyph(Stream glyphImageStream)

{         
       var image = new System.Drawing.Bitmap(glyphImageStream);
        // paint glyph in image center
        var fixImage = new System.Drawing.Bitmap(160, 240);
        using (Graphics g = Graphics.FromImage(fixImage))
       

{             g.DrawImage(image, new RectangleF(20, 20, fixImage.Width - 40, fixImage.Height - 40), new RectangleF(0, 0, image.Width, image.Height), GraphicsUnit.Pixel);         }
        var unicodeResult = _engine.DetectText(fixImage).Text;
        return unicodeResult;
}

}