> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/uwp/get-started/samples/pagelabelstest.md). # PageLabels Sample C# code for using Apryse SDK to work with PDF page labels. PDF page labels can be used to describe a page, which is used to allow for non-sequential page numbering or the addition of arbitrary Sample C# code for using Apryse SDK to work with PDF page labels. PDF page labels can be used to describe a page, which is used to allow for non-sequential page numbering or the addition of arbitrary labels for a page (such as the inclusion of Roman numerals at the beginning of a book). Learn more about our [UWP SDK](/core/get-started/frameworks/dotnet.md) and [PDF Editing & Manipulation Library](/core/page-manipulation/manipulation.md). {% tabs %} {% tab title="C#" %} {% code lineNumbers="true" %} ```csharp // // Copyright (c) 2001-2020 by PDFTron Systems Inc. All Rights Reserved. // using System; using System.IO; using System.Threading.Tasks; using Windows.Foundation; using pdftron.PDF; using pdftron.SDF; using PDFNetUniversalSamples.ViewModels; namespace PDFNetSamples { public sealed class PageLabelsTest : Sample { public PageLabelsTest() : base("PageLabels", "This example illustrates how to work with PDF page labels. PDF page labels can be used to describe a page. This is used to allow for non-sequential page numbering or the addition of arbitrary labels for a page (such as the inclusion of Roman numerals at the beginning of a book).") { } public override IAsyncAction RunAsync() { return Task.Run(new System.Action(async () => { WriteLine("--------------------------------"); WriteLine("Starting Annotation Test..."); WriteLine("--------------------------------\n"); try { //----------------------------------------------------------- // Example 1: Add page labels to an existing or newly created PDF // document. //----------------------------------------------------------- { string input_file_path = Path.Combine(InputPath, "newsletter.pdf"); WriteLine("Opening input file " + input_file_path); PDFDoc doc = new PDFDoc(input_file_path); doc.InitSecurityHandler(); // Create a page labeling scheme that starts with the first page in // the document (page 1) and is using uppercase roman numbering // style. doc.SetPageLabel(1, PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_roman_uppercase, "My Prefix ", 1)); // Create a page labeling scheme that starts with the fourth page in // the document and is using decimal arabic numbering style. // Also the numeric portion of the first label should start with number // 4 (otherwise the first label would be "My Prefix 1"). PageLabel L2 = PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_decimal, "My Prefix ", 4); doc.SetPageLabel(4, L2); // Create a page labeling scheme that starts with the seventh page in // the document and is using alphabetic numbering style. The numeric // portion of the first label should start with number 1. PageLabel L3 = PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_alphabetic_uppercase, "My Prefix ", 1); doc.SetPageLabel(7, L3); String output_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf"); await doc.SaveAsync(output_file_path, SDFDocSaveOptions.e_linearized); WriteLine("Done. Results saved in " + output_file_path); await AddFileToOutputList(output_file_path).ConfigureAwait(false); doc.Destroy(); } //----------------------------------------------------------- // Example 2: Read page labels from an existing PDF document. //----------------------------------------------------------- { string input_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf"); WriteLine("Opening file " + input_file_path); PDFDoc doc = new PDFDoc(input_file_path); doc.InitSecurityHandler(); PageLabel label; int page_num = doc.GetPageCount(); for (int i=1; i<=page_num; ++i) { WriteLine(string.Format("Page number: {0}", i)); label = doc.GetPageLabel(i); if (label.IsValid()) { WriteLine(string.Format(" Label: {0}", label.GetLabelTitle(i))); } else { WriteLine(" No Label."); } } doc.Destroy(); } //----------------------------------------------------------- // Example 3: Modify page labels from an existing PDF document. //----------------------------------------------------------- { string input_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf"); WriteLine("Opening file " + input_file_path); PDFDoc doc = new PDFDoc(input_file_path); doc.InitSecurityHandler(); // Remove the alphabetic labels from example 1. doc.RemovePageLabel(7); // Replace the Prefix in the decimal lables (from example 1). PageLabel label = doc.GetPageLabel(4); if (label.IsValid()) { label.SetPrefix("A"); label.SetStart(1); } // Add a new label PageLabel new_label = PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_decimal, "B", 1); doc.SetPageLabel(10, new_label); // starting from page 10. String output_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels_modified.pdf"); await doc.SaveAsync(output_file_path, SDFDocSaveOptions.e_linearized); WriteLine("Done. Results saved in " + output_file_path); await AddFileToOutputList(output_file_path).ConfigureAwait(false); int page_num = doc.GetPageCount(); for (int i=1; i<=page_num; ++i) { WriteLine(string.Format("Page number: {0}", i)); label = doc.GetPageLabel(i); if (label.IsValid()) { WriteLine(string.Format(" Label: {0}", label.GetLabelTitle(i))); } else { WriteLine(" No Label."); } } doc.Destroy(); } //----------------------------------------------------------- // Example 4: Delete all page labels in an existing PDF document. //----------------------------------------------------------- { PDFDoc doc = new PDFDoc(Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf")); //doc.GetRoot().Erase("PageLabels"); // ... doc.Destroy(); } } catch (Exception e) { WriteLine(GetExceptionMessage(e)); } WriteLine("\n--------------------------------"); WriteLine("Done PageLabels Test."); WriteLine("--------------------------------\n"); })).AsAsyncAction(); } } } ``` {% endcode %} {% endtab %} {% endtabs %} --- # Agent Instructions This documentation is published with GitBook. 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