PM> Install-Package Spire.Doc

using Spire.Doc;
namespace ConvertWordToXps
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Document instance
            Document doc = new Document();
            //Load a Word document
            doc.LoadFromFile("Sample.docx");
            //convert the document to XPS
            doc.SaveToFile("ToXPS.xps", FileFormat.XPS);
        }
    }
}

Imports Spire.Doc

Namespace ConvertWordToXps
    Friend Class Program
        Private Shared Sub Main(ByVal args As String())
            'Create a Document instance
            Dim doc As Document = New Document()
            'Load a Word document
            doc.LoadFromFile("Sample.docx")
            'convert the document to XPS
            doc.SaveToFile("ToXPS.xps", FileFormat.XPS)
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.Doc

using Spire.Doc;

namespace WordtoEPUB
{
    class Epub
    {
        static void Main(string[] args)
        {
            //Create a Document instance
            Document document = new Document();

            //Load a sample Word document
            document.LoadFromFile("demo.docx");

            //Convert the Word document to EPUB
            document.SaveToFile("ToEpub.epub", FileFormat.EPub);
        }
    }
}

Imports Spire.Doc

Namespace WordtoEPUB
    Class Epub
        Private Shared Sub Main(ByVal args As String())

            'Create a Document instance
            Dim document As Document = New Document()

            'Load a sample Word document
            document.LoadFromFile("demo.docx")

            'Convert the Word document to EPUB
            document.SaveToFile("ToEpub.epub", FileFormat.EPub)
        End Sub
    End Class
End Namespace 

using Spire.Doc;
using Spire.Doc.Fields;
using System.Drawing;

namespace ConvertWordToEpubWithCoverImage
{
    class Program
    {
        static void Main(string[] args)
        {

            //Create a Document instance
            Document doc = new Document();

            //Load a sample Word document
            doc.LoadFromFile("demo.docx");

            //Create a DocPicture instance
            DocPicture picture = new DocPicture(doc);

            //Load an image
            picture.LoadImage(Image.FromFile("CoverImage.png"));

            //Save the Word document to EPUB with cover image
            doc.SaveToEpub("ToEpubWithCoverImage.epub", picture);
        }
    }
}

Imports Spire.Doc
Imports Spire.Doc.Fields

Namespace ConvertWordToEpubWithCoverImage
    Class Program
        Private Shared Sub Main(ByVal args As String())

            'Create a Document instance
            Dim doc As Document = New Document()

            'Load a sample Word document
            doc.LoadFromFile("demo.docx")

            'Create a DocPicture instance
            Dim picture As DocPicture = New DocPicture(doc)

            'Load an image
            picture.LoadImage(Image.FromFile("CoverImage.png"))

            'Save the Word document to EPUB with cover image
            doc.SaveToEpub("ToEpubWithCoverImage.epub", picture)
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.Doc

using Spire.Doc;
using Spire.Doc.Documents;
using System.Drawing;
using System.Drawing.Imaging;

namespace ConvertHtmlFileToPng
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Document object
            Document document = new Document();

            // Load an HTML file
            document.LoadFromFile(@"C:\Users\Administrator\Desktop\MyHtml.html", FileFormat.Html, XHTMLValidationType.None);

            // Get the first section
            Section section = document.Sections[0];

            // Set the page margins
            section.PageSetup.Margins.All = 2;

            // Convert the document to an array of bitmap images
            Image[] images = document.SaveToImages(ImageType.Bitmap);

            // Iterate through the images
            for (int index = 0; index < images.Length; index++)
            {
                // Specify the output file name
                string fileName = string.Format(@"C:\Users\Administrator\Desktop\Output\image_{0}.png", index);

                // Save each image as a PNG file
                images[index].Save(fileName, ImageFormat.Png);
  
            }

            // Dispose resources
            document.Dispose();
        }
    }
}

using Spire.Doc;
using Spire.Doc.Documents;
using System.Drawing;
using System.Drawing.Imaging;

namespace ConvertHtmlStringToPng
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Document object
            Document document = new Document();

            // Add a section to the document
            Section section = document.AddSection();

            // Set the page margins
            section.PageSetup.Margins.All = 2;

            // Add a paragraph to the section
            Paragraph paragraph = section.AddParagraph();

            // Read HTML string from a file 
            string htmlFilePath = @"C:\Users\Administrator\Desktop\Html.html";
            string htmlString = File.ReadAllText(htmlFilePath, System.Text.Encoding.UTF8);

            // Append the HTML string to the paragraph
            paragraph.AppendHTML(htmlString);

            // Convert the document to an array of bitmap images
            Image[] images = document.SaveToImages(ImageType.Bitmap);

            // Iterate through the images
            for (int index = 0; index < images.Length; index++)
            {
                // Specify the output file name
                string fileName = string.Format(@"C:\Users\Administrator\Desktop\Output\image_{0}.png", index);

                // Save each image as a PNG file
                images[index].Save(fileName, ImageFormat.Png);

            }

            // Dispose resources
            document.Dispose();
        }
    }
}