Aspose.PDF for .NET 25.6

    // For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
    private static void GetSetAlternativeTextForImage()
    {
        // The path to the documents directory
        var dataDir = RunExamples.GetDataDir_AsposePdf_Images();

        // Open PDF document
        using (var document = new Aspose.Pdf.Document(dataDir + "SearchAndGetImages.pdf"))
        {
            // Alternative text to be given to the image 
            string altText = "Alternative text for image";

            // Image for which alternative text will be set and get
            XImage xImage = document.Pages[1].Resources.Images[1];

            // Try to set alternative text for an image
            bool result = xImage.TrySetAlternativeText(altText, document.Pages[1]);

            // If set is successful, then get the alternative text for the image
            if (result)
            {
                List<string> altTexts = xImage.GetAlternativeText(document.Pages[1]);
            }

            // Save PDF document
            document.Save(dataDir + "SearchAndGetImagesWithAltText_out.pdf");
        }
    }

    // For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
    private static void GetLicenseInfoExample(string pathToLicenseFile)
    {
        // Initialize license object
        var lic = new Aspose.Pdf.License();
        // Set license
        lic.SetLicense(pathToLicenseFile);
        // Get licecnse info.
        var licLicenseInfo = lic.LicenseInfo;
    
        Console.WriteLine(licLicenseInfo.LicensedTo);
        Console.WriteLine(licLicenseInfo.SubscriptionExpiry);
    }

    private static void InterruptMonitorHtmlExample()
    {
        // The path to the documents directory
        var dataDir = RunExamples.GetDataDir_AsposePdf_Text();
        // Path to a large text file 
        var longHtmlFile = dataDir + "LongHtmlFile.html";
        var outputFile = dataDir + "interrupt_from_html_output.pdf";

        // Create an InterruptMonitor instance
        using (InterruptMonitor monitor = new InterruptMonitor())
        {
            //document LongHtmlFile.html takes around 10 hours to complete all conversions
            var worker = new HtmlToPdfDocumentWorker(longHtmlFile), outputFile, monitor);
            Thread thread = new Thread(new ThreadStart(worker.DoWork));
            thread.Start();

            // The timeout should be less than the time required for full document save (without interruption).
            Thread.Sleep(2000);

            // Interrupt the process
            monitor.Interrupt();

            // Wait for interruption...
            thread.Join();
        }
    }

    // Helper class to demonstrate how to handle PDF generation with interruption support
    private class HtmlToPdfDocumentWorker
    {
        /// <summary>
        /// The path to the input file.
        /// </summary>
        private readonly string inputPath;

        /// <summary>
        /// The path to the output file.
        /// </summary>
        private readonly string outputPath;

        /// <summary>
        /// The interrupt monitor.
        /// </summary>
        private readonly InterruptMonitor monitor;

        public HtmlToPdfDocumentWorker(string inputPath, string outputPath, InterruptMonitor monitor)
        {
            this.inputPath = inputPath;
            this.outputPath = outputPath;
            this.monitor = monitor;
        }
        public void DoWork()
        {
            using (Document doc = new Document())
            {
                InterruptMonitor.ThreadLocalInstance = this.monitor;
                Page page = doc.Pages.Add();
                string strFinalHtml = File.ReadAllText(this.inputPath);
                HtmlFragment htmlFragment = new HtmlFragment(strFinalHtml);
                page.Paragraphs.Add(htmlFragment);
                try
                {
                    doc.Save(this.outputPath);
                }
                catch (OperationCanceledException ex)
                {
                    Console.WriteLine($"Operation cancelled: {ex.Message}");
                }
            }
        }
    }

    // For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
    private static void AddFreeAnnotationAndSetStyles()
    {
        // The path to the documents directory
        var dataDir = RunExamples.GetDataDir_AsposePdf_Annotations();

        // Open PDF document
        using (var document = new Aspose.Pdf.Document(dataDir + "SetFreeTextAnnotationFormatting.pdf"))
        {
            // Add new page
            Page page = document.Pages.Add();

            // Instantiate DefaultAppearance object
            var defaultAppearance = new Aspose.Pdf.Annotations.DefaultAppearance("Arial", 16, System.Drawing.Color.Blue);

            // Create annotation
            var freetext = new Aspose.Pdf.Annotations.FreeTextAnnotation(page, new Aspose.Pdf.Rectangle(20, 600, 400, 650), defaultAppearance);

            // Specify the contents of annotation
            freetext.Contents = "Text of FreeTextAnnotation with different styles";

            // Add annotation to annotations collection of page
            page.Annotations.Add(freetext);

            // Set styles for annotation text
            freetext.SetTextStyle(0, 4, RichTextFontStyles.Italic);
            freetext.SetTextStyle(8, 26, RichTextFontStyles.Underline | RichTextFontStyles.Bold);
            freetext.SetTextStyle(27, 86, RichTextFontStyles.Bold);
            freetext.SetTextStyle(42, 45, RichTextFontStyles.ClearExisting | RichTextFontStyles.Underline);

            // Save PDF document
            document.Save(dataDir + "SetFreeTextAnnotationFormatting_out.pdf");
        }
    }

    // For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
    private static void CustomizationFeaturesForDigitalSign()
    {
        // The path to the image.
        var imagePath = RunExamples.GetDataDir_AsposePdf_StampsWatermarks() + "aspose-logo.jpg";
        // The path to the documents directory
        var dataDir = RunExamples.GetDataDir_AsposePdf_SecuritySignatures();

        using (var pdfFileSignature = new Aspose.Pdf.Facades.PdfFileSignature())
        {
            // Bind PDF document
            pdfFileSignature.BindPdf(dataDir + "input.pdf");

            // Create a rectangle for signature location
            System.Drawing.Rectangle rect = new System.Drawing.Rectangle(10, 10, 300, 50);

            // Create any of the three signature types
            var signature = new Aspose.Pdf.Forms.PKCS1(dataDir + "rsa_cert.pfx", "12345"); // PKCS#1
            // Create signature appearance
            var signatureCustomAppearance = new Aspose.Pdf.Forms.SignatureCustomAppearance
            {
                FontSize = 6,
                FontFamilyName = "Times New Roman",
                DigitalSignedLabel = "Signed by:",
                IsForegroundImage = true
            };
            // Set signature appearance
            signature.CustomAppearance = signatureCustomAppearance;
            // Set signature appearance
            pdfFileSignature.SignatureAppearance = imagePath;

            pdfFileSignature.Sign(1, true, rect, signature);
            // Save PDF document
            pdfFileSignature.Save(dataDir + "DigitallySign_out.pdf");
        }
    }