Aspose.PDF.FOSS 26.8.0

Aspose.PDF FOSS for .NET

Aspose.PDF FOSS for .NET is a free, open-source PDF library for .NET 8+ that reads, creates, modifies, and converts PDF documents. It provides an Aspose.PDF-compatible API surface for common PDF scenarios, so a large part of existing Aspose.PDF for .NET code can compile and run against it unchanged.

Navigation

• At a Glance
• Key Capabilities
• Installation
• Quick Start
• Additional Examples
• API Reference
• Documentation & Resources
• Scope and Limitations
• Development and Testing
• License

At a Glance

Key Capabilities

• Open an existing PDF or create one from scratch with Document, then add, delete, reorder, rotate, resize, or copy pages across documents through Page and PageCollection; full round-trip save and incremental save preserve bookmarks and outlines, page labels, named destinations, document info, XMP metadata, and optional content (OCG) layers.
• Standard 14 font handling, TrueType / OpenType embedding and subsetting, and Type 1 (PostScript) and Type 3 font parsing are handled through FontRepository and FontEmbedder.
• Extract text with TextAbsorber, TextFragmentAbsorber, ParagraphAbsorber, and TableAbsorber; find and replace across pages — including cross-operator and ligature-aware spans — and build new text with TextBuilder, TextFragment, TextSegment, TextStamp, and FormattedText, with Bidi (RTL) support and AGL Unicode mapping.
• Read, fill, and build AcroForm fields — text, checkbox, radio, choice, button, signature, and rich text — through Form, Field, FormFieldBuilder, FormEditor, and FormDataConverter, including field-level flatten and JSON/XFDF form-data import and export.
• Add and edit every standard annotation type — link, text, free-text, highlight, square/circle/line/polyline, ink, stamp, popup, file attachment, screen, redaction, watermark, pre-press marks, and rich media — with appearance generation and flatten.
• Encrypt and decrypt with RC4-40, RC4-128, AES-128, and AES-256, and sign documents with PKCS#7 / CMS detached signatures — including DocMDP certifying signatures — through PdfFileSecurity, PdfFileSignature, PdfSigner, and PdfCertificate; document permissions can be read and set directly on Document.
• Render pages to PNG, JPEG, BMP, TIFF, or SVG with PngDevice, JpegDevice, BmpDevice, TiffDevice, and SvgDevice through the pluggable IPageRenderer (default SoftwarePageRenderer), with mesh shading types 4-7 (free-form and lattice-form Gouraud, Coons, and tensor-product patch meshes), a JBIG2 decoder, and JPEG / JPEG2000 / CCITT-Fax filters.
• Convert PDF to and from HTML and SVG, load Markdown, XML, or plain-text (TXT) files, and export to Markdown, plain text, or PDF/A (1A through 4F), using HtmlLoadOptions / HtmlSaveOptions, SvgLoadOptions, MdLoadOptions, and TxtLoadOptions.
• High-level, task-oriented facades cover common workflows: PdfFileEditor for concatenate/split/resize/extract, PdfBookmarkEditor for outline CRUD with XML/HTML export, PdfContentEditor for annotations/stamps/replace-text, PdfFileStamp for header/footer/ page-number stamping, plus PdfFileInfo, PdfFileMend, PdfAnnotationEditor, PdfPageEditor, PdfConverter, PdfExtractor, and PdfViewer.
• Read an existing /StructTreeRoot tree and walk its Aspose.Pdf.LogicalStructure element hierarchy, or build tagged content from scratch with ITaggedContent's 37 typed structure elements, setting document language, title, alternate text, and marked content for accessibility.
• Compare two documents or two pages: SideBySidePdfComparer writes a result PDF that sets both versions side by side with deletions marked on the left and insertions on the right, with whitespace handling, comparison / exclusion areas, and marker colours set through SideBySideComparisonOptions; GraphicalPdfComparer diffs the rendered pixels of two pages (Windows only), and the Aspose.Pdf.Comparison.Diff model sits under both.
• Extract tabular data and build tables with Table, Row, Cell, and TableAbsorber; draw with Graph, Rectangle, Circle, Ellipse, Arc, Line, and Curve; and extract or place images through ImagePlacementAbsorber and XImageCollection.

Installation

This library publishes prebuilt binaries to NuGet as Aspose.PDF.FOSS:

dotnet add package Aspose.PDF.FOSS --version 26.8.0

Or with a <PackageReference>:

<PackageReference Include="Aspose.PDF.FOSS" Version="26.8.0" />

The library targets .NET 8.0 and pulls in one NuGet dependency, System.Drawing.Common (8.0.0), used only by a few image-interop members (e.g. ImageDevice.GetBitmap, StampInfo.Image). Those specific members are Windows-only on .NET 8 and throw PlatformNotSupportedException on Linux/macOS — use the byte-array / Stream overloads instead, or read raw pixel data directly from the renderer's RgbaBuffer. Everything else — text, forms, parsing, encryption and signing, and page-to-image rendering via PngDevice/JpegDevice (backed by the built-in managed SoftwarePageRenderer, used automatically off Windows) — is pure-managed and runs on Windows, Linux, and macOS.

To build from source instead:

git clone https://github.com/aspose-pdf-foss/Aspose.PDF-FOSS-for-.NET.git
cd Aspose.PDF-FOSS-for-.NET
dotnet build src/Aspose.Pdf.Foss.csproj -c Release

Then reference src/Aspose.Pdf.Foss.csproj from your project (e.g. dotnet add reference), or add the built Aspose.Pdf.Foss.dll as an assembly reference.

Dependencies

Required Package Dependencies

• System.Drawing.Common (8.0.0) — used only by a few image-interop members (e.g. ImageDevice.GetBitmap, StampInfo.Image). Those specific members are Windows-only on .NET 8 and throw PlatformNotSupportedException on Linux/macOS; everything else in the library is pure-managed and cross-platform.

Optional Dependencies

No optional third-party package dependencies.

Native and System Requirements

• .NET 8.0 or later, running on Windows, Linux, or macOS.

Development Dependencies

No development-only third-party package dependencies beyond the standard .NET SDK/test tooling used to build and run the test suite (see Development and Testing).

Quick Start

Create a new PDF, then open an existing one and extract its text:

using Aspose.Pdf;
using Aspose.Pdf.Text;

// Create a new PDF document
using var doc = Document.Create();
var page = doc.Pages.Add();
var fragment = new TextFragment("Hello, World!");
fragment.TextState.FontSize = 24;
page.Paragraphs.Add(fragment);
doc.Save("output.pdf");

// Open an existing PDF and extract its text
using var existing = Document.Open("input.pdf");
var absorber = new TextAbsorber();
absorber.Visit(existing.Pages[1]);
Console.WriteLine(absorber.Text);

Additional Examples

More real, runnable examples, adapted from the library's own test suite.

Add a Link Annotation With a URI Action

using Aspose.Pdf;
using Aspose.Pdf.Annotations;

using var doc = Document.Open("input.pdf");
var page = doc.Pages[1];

var action = PdfAction.CreateUri("https://example.org");
page.Annotations.AddLinkAnnotation(new Rectangle(10, 10, 100, 30), action);

doc.Save("output.pdf");

<details> <summary>View Additional Examples</summary>

Find Matching Text

using Aspose.Pdf;
using Aspose.Pdf.Text;

using var doc = Document.Open("input.pdf");
var absorber = new TextFragmentAbsorber("Hello");
absorber.Visit(doc.Pages[1]);
Console.WriteLine($"Found {absorber.TextFragments.Count} matches");

Add a Stamp Annotation

using Aspose.Pdf;

using var doc = Document.Open("input.pdf");
doc.Pages[1].Annotations.AddStampAnnotation(
    new Rectangle(100, 700, 200, 750), "Approved!", "Approved");
doc.Save("output.pdf");

Inspect a Choice Field's Options

using Aspose.Pdf;
using Aspose.Pdf.Forms;

using var doc = Document.Open("form.pdf");
var field = (ChoiceField)doc.Form!.Fields[0];
var options = field.Options;
for (int i = 1; i <= options.Count; i++)
    Console.WriteLine($"{options[i].ExportValue}: {options[i].DisplayValue}");

Render a Page to SVG

using Aspose.Pdf;
using Aspose.Pdf.Devices;

using var doc = Document.Open("input.pdf");
var device = new SvgDevice();
string svg = device.Process(doc.Pages[1]);
File.WriteAllText("page1.svg", svg);

Find and Replace Text

using Aspose.Pdf;
using Aspose.Pdf.Text;

using var doc = Document.Open("input.pdf");
var absorber = new TextFragmentAbsorber("old text");
absorber.Visit(doc);

foreach (var fragment in absorber.TextFragments)
    fragment.Text = "new text";

doc.Save("output.pdf");

List Form Field Values

using Aspose.Pdf;

using var doc = Document.Open("form.pdf");
foreach (var field in doc.Form!.Fields)
    Console.WriteLine($"{field.FullName} = {field.Value}");

Encrypt a PDF

using Aspose.Pdf;

using var doc = Document.Open("input.pdf");
doc.Encrypt("user-pw", "owner-pw", Permissions.PrintDocument, CryptoAlgorithm.AESx256);
doc.Save("encrypted.pdf");

Convert HTML to PDF

using Aspose.Pdf;

using var doc = Document.Open("input.html", new HtmlLoadOptions());
doc.Save("output.pdf");

Render a Page to PNG

using Aspose.Pdf;
using Aspose.Pdf.Devices;

using var doc = Document.Open("input.pdf");
var device = new PngDevice(new Resolution(300));
device.Process(doc.Pages[1], "page1.png");

Sign a PDF

using Aspose.Pdf.Facades;
using Aspose.Pdf.Forms;

using var signer = new PdfFileSignature();
signer.BindPdf("input.pdf");
var sig = new PKCS7("my.pfx", "pfx-password");
signer.Sign(1, "reason", "contact", "location", true,
    new System.Drawing.Rectangle(100, 100, 200, 60), sig);
signer.Save("signed.pdf");

</details>

API Reference

The primary entry point is Document, which exposes its pages through Document.Pages (a PageCollection of Page objects), its interactive form through Document.Form, and its security surface through PdfFileSecurity and PdfFileSignature. The public API surface includes 854 public types across 36 modules, summarized in the module-grouped tables below.

<details> <summary>View the Core API Surface</summary>

Core API

Class	Description
BaseOperatorCollection	Standalone operator-list class — surface mirrors OperatorCollection but is detached from any page.
BuildVersionInfo	Build and version information for the library.
CollectionItem	Per-file metadata entries declared by a portfolio /Collection's schema, exposed as a typed dictionary on CollectionItem.
ContentsAppender	Buffers operators to prepend to / append to a page's content stream.
Document	Represents a PDF document.
DocumentCollection	Enumerable collection of Document instances; GetEnumerator() throws NotImplementedException in this edition (see Scope and Limitations).
DocumentInfo	Represents the document information dictionary.
EmbeddedFileCollection	Collection of embedded files in a document.
EncryptedPayload	Wraps the /EP entry on an embedded-file file-spec — the encrypted-payload that signals a PDF 2.0 unencrypted-wrapper document.
EngineDocFacade	Wrapper providing the small slice of engine-level state callers may set via doc._engineDoc.X.
ExtGStateValue	One /ExtGState entry — name plus stroke/fill alpha factors.
FileParams	Wraps the /Params dict on an embedded-file stream (PDF §7.11.3 Table 46).
FileSpecification	Represents an embedded file specification (PDF §7.11.3).
Group	Group / blending colour space dictionary (PDF 32000 §11.6.5).
Image	Image compositing can be customized using the BlendMode enumeration, which includes common blend operations such as Multiply and Screen.
ImagePlacement	Represents an image placement found on a PDF page — the position, size, and resolution of an image XObject as it appears on the page (after CTM transformation).
ImagePlacementAbsorber	Absorbs image placement information from PDF pages.
ImagePlacementCollection	A collection of ImagePlacement items.
ImageStamp	Adds an image to a PDF page.
InterruptMonitor	Class with 1 method.
JavaScriptCollection	Document-level JavaScript scripts (PDF spec §12.6.4.16).
LaunchActionOperationConverter	LaunchActionOperationConverter converts a LaunchActionOperation value to its string representation via ToString, exposing the strings strOpen and strPrint.
Layer	A PDF layer (Optional Content Group) as exposed through Layers.
MergeOptions	Merge tuning knobs honored by Merge(MergeOptions, Document[]) and friends.
OcspSettings	OCSP (Online Certificate Status Protocol) settings for the signer's revocation-check / OCSP-stapling path.
Operator-Pdf	Top-level base for all PDF content-stream operators.
OperatorCollection	Collection of content stream operators for a page.
Opi	Open Prepress Interface (OPI) metadata wrapper for an XForm.
OptimizationOptions-Pdf	Document-scoped alias for OptimizationOptions.
Page	Represents a page in a PDF document.
PageActionCollection	Per-page additional actions (PDF 32000 §12.6.3 /AA entries).
PageExtensions	Extension methods over Page that manipulate the page content stream.
PageInfo	Container for page dimension and margin properties.
PageResources	Provides access to a page's resource collections (fonts, images).
PageTransition	Represents a page transition effect (PDF32000 §12.4.4).
RawOperator	An unparsed operator token from a content stream — used as a fallback for operators not covered by the typed Operators hierarchy.
RepairOptions	Options describing what repair is needed.
Resolution	Represents the resolution (DPI) for device rendering and image placement.
Resources	Type alias for PageResources, matching the Resources class name.
Stamp-Pdf	Top-level Aspose.Pdf-shape abstract base for stamps applied to a Page via AddStamp(Stamp).
TextStamp-Pdf	Compat re-export so external tests that reference Aspose.Pdf.TextStamp (from before the type moved to Aspose.Pdf.Stamps) keep compiling.
TimestampSettings	RFC 3161 Time-Stamp Authority (TSA) settings consumed by the signer when embedding a timestamp token into the PKCS#7 envelope.
Value	One typed value pulled out of a CollectionItem dict by TryGet*Value.
WarningInfo	Class with 2 methods and 3 properties.
Watermark	Watermark applied to a page.
XForm	Represents a Form XObject (reusable content stream with its own resources).
XFormCollection	Collection of XForm (Form XObject) resources on a page.
XFormResources	Resources (fonts, xobjects) on an XForm's stream dict.

Interfaces

Interface	Description
IDocumentFontUtilities	Per-document font helper contract — implemented by FontUtilities.
IOperatorSelector	Visitor interface for Accept(IOperatorSelector).
IWarningCallback	Interface with 1 method.

Enumerations

Enumeration	Description
AFRelationship	Relationship between an embedded file and the document content that references it (/AFRelationship, PDF 2.0 §7.11.3).
FileEncoding	Compression / encoding used for the embedded file stream's data (consumed by Encoding).
Fixup	Pre-defined PDF fixup operations accepted by Stream, bool, object[]).
ImageDeleteAction	Action taken by Delete(int, ImageDeleteAction) when the image being removed is still referenced from the page content.
ImageFileType	Recognised image-source file types reported by Image.FileType.
ImageFilterType	ImageFilterType enum defines the compression filters Jpeg2000, Flate, Jpeg, and CCITTFax that can be applied when re‑encoding images.
LaunchActionOperation	LaunchActionOperation enum defines the possible launch operations: None, Open, and Print.
NoCharacterAction-Pdf	Action taken when the configured font does not have a glyph for a character in the stamp text.
PasswordType	Identifies which password (if any) is in effect on an encrypted PDF.
PdfAStandardVersion	PdfAStandardVersion enum lists supported PDF/A conformance levels, including PDF_A_1A, PDF_A_2B, PDF_A_3U, and PDF_A_4.
Permissions	Permissions.PrintDocument, ModifyContent, ExtractContent, etc., are enum values that can be combined to set document security settings.
PrintScaling	Enum with 2 members.
ReturnAction	The ReturnAction enum is used by RichMediaAnnotation.Accept(visitor) to indicate whether the visitor should Continue processing or Abort.
Rotation	Enum with 5 members.
TabOrder	Tab order applied to widget annotations on a page (PDF 32000 /Tabs entry).
WarningType	Categories of warnings emitted during save/load.

Actions

Class	Description
ActionCollection	Collection of actions associated with an annotation.
GoToAction	Class with 13 methods and 5 properties.
GoToRemoteAction	Go-to-remote action — jumps to a destination in a different PDF file .
GoToURIAction	Alias for UriAction, matching the public API name.
ImportDataAction	An import-data action (/S /ImportData): imports field data from the FDF/XFDF file identified by the action's /F file specification.
JavascriptAction	Class with 8 methods and 3 properties.
LaunchAction	Class with 9 methods and 4 properties.
NamedAction	NamedAction.CreateUri(uri) builds a URI action that can be linked to from annotations or form fields.
PdfAction	Base class for PDF actions.
SubmitFormAction	Submit-form action — sends form field data to a URL or remote file (PDF 32000-1:2008 §12.7.5.2).
UriAction	Class with 7 methods and 3 properties.

Enumerations

Enumeration	Description
ActionType	The type of a PDF action.

Annotations

Class	Description
Annotation	Represents a PDF annotation.
AnnotationActionCollection	Per-event PDF action slots for a widget annotation (matches the Aspose.Pdf /AA-tree entry shape: 14 named events plus the direct /A activation action).
AnnotationCollection	Collection of annotations on a page.
AnnotationSelector	Visitor that filters annotations across one or more pages.
AppearanceDictionary	Appearance-stream dictionary on an annotation (/AP entry): maps appearance-state name → XForm.
BleedMarkAnnotation	BleedMarkAnnotation can be instantiated with a page and position, and provides methods to update its appearance, flatten it, and write XFDF data.
Border	Represents the border of an annotation or field widget.
CaretAnnotation	Class with 16 methods and 52 properties.
Characteristics	Annotation characteristics (border, rotation, etc.).
CircleAnnotation	Class with 16 methods and 51 properties.
ColorBarAnnotation	The ColorBarAnnotation constructor creates a color‑bar annotation on a page by specifying the page, rectangle and a CMYK color selector.
CommonFigureAnnotation	Common base for square and circle annotations — a figure drawn inside a rectangle, optionally inset by /RD (PDF 32000 §12.5.6.8).
Dash	Represents a dash pattern for borders.
DefaultAppearance	Represents the default appearance of a free text annotation.
DocumentActionCollection	Document-level /AA additional-action dictionary (PDF 32000-1 §12.6.3 Table 195).
ExplicitDestination	Represents an explicit destination in a PDF document (e.g.
FieldDateTimeFormatter	Formats a date/time value string according to an Acrobat-style date format.
FieldNumberCurrencyFormatter	Formats a numeric string as a currency value.
FieldNumberPercentFormatter	Formats a numeric string as a percentage (multiplies by 100 first).
FileAttachmentAnnotation	Represents a file attachment annotation.
FitBExplicitDestination	Fit-bounding-box destination (/FitB).
FitBHExplicitDestination	FitBH destination (/FitBH) — fit bounding box horizontally at Top.
FitBVExplicitDestination	FitBV destination (/FitBV) — fit bounding box vertically at Left.
FitExplicitDestination	Fit-the-page destination (/Fit).
FitHExplicitDestination	Fit horizontally at /Top (/FitH).
FitRExplicitDestination	FitR rectangle destination (/FitR).
FitVExplicitDestination	Fit vertically at /Left (/FitV).
FixedPrint	Class with 3 properties.
FreeTextAnnotation	FreeTextAnnotation constructors allow creating a free‑text annotation on a specific page rectangle with a defined appearance.
GenericAnnotation	Fallback annotation class for annotation subtypes that have no dedicated model (e.g.
HighlightAnnotation	Highlight text markup annotation.
InkAnnotation	Class with 17 methods and 52 properties.
LineAnnotation	Class with 17 methods and 62 properties.
LinkAnnotation	Class with 9 methods and 51 properties.
MarkupAnnotation	Class with 15 methods and 50 properties.
Measure	Measure-units metadata attached to a LineAnnotation (PDF 32000 §12.5.6.13 measure dictionaries).
MediaClip	A media clip object (PDF §13.2.4) — the actual media data or section thereof.
MediaClipData	A media clip data object (PDF §13.2.4.2) — full media data via a file specification.
MediaClipSection	A media clip section object (PDF §13.2.4.3) — a temporal section of another clip.
MediaRendition	A media rendition (PDF §13.2.3.2) — pairs a media clip with playback parameters.
MovieAnnotation	Class with 9 methods and 51 properties.
NumberFormat	One number-format entry — describes how a measurement value is rendered (precision, separators, before/after text).
NumberFormatList	Nested number-format list (Aspose.Pdf shape: Measure+NumberFormatList).
PDF3DAnnotation	Class with 14 methods and 53 properties.
PDF3DArtwork	A 3D artwork dictionary referenced by a PDF 3D annotation (Aspose.Pdf shape).
PDF3DContent	Embedded-stream content for a 3D artwork (U3D or PRC).
PDF3DCrossSection	Single cross-section through a PDF 3D model (Aspose.Pdf shape).
PDF3DCrossSectionArray	Ordered collection of PDF3DCrossSection entries applied to a PDF 3D view (Aspose.Pdf shape).
PDF3DCuttingPlaneOrientation	Orientation angles for the cutting plane of a 3D cross-section (Aspose.Pdf shape).
PDF3DLightingScheme	Lighting scheme applied to a PDF 3D artwork (Aspose.Pdf shape).
PDF3DRenderMode	Render mode applied to a 3D artwork view (Aspose.Pdf shape).
PDF3DStream	PDF /3DD stream wrapper — pairs a PDF3DArtwork with its document-owned content stream.
PDF3DView	Camera + render-state snapshot of a 3D artwork (Aspose.Pdf shape).
PDF3DViewArray	Indexed collection of PDF3DView snapshots (Aspose.Pdf shape).
PageInformationAnnotation	Class with 8 methods and 47 properties.
PdfActionCollection	Collection of PdfAction entries attached to an annotation (or any other action-bearing PDF object).
PolyAnnotation	Common base for polygon and polyline annotations — a chain of connected vertices (PDF 32000 §12.5.6.9).
PolygonAnnotation	Class with 16 methods and 52 properties.
PolylineAnnotation	Class with 15 methods and 52 properties.
PopupAnnotation	Class with 9 methods and 49 properties.
PrinterMarkAnnotation	Aggregate printer's-mark generator.
RedactAnnotation	Backward-compatible alias for RedactionAnnotation.
RedactionAnnotation	Represents a redaction annotation.
RegistrationMarkAnnotation	Class with 8 methods and 48 properties.
Rendition	A rendition object (PDF §13.2.3) — describes a media object to be played by a rendition action.
RenditionAction	A rendition action (PDF §12.6.4.14) — controls the playing of multimedia content.
RichMediaAnnotation	Class with 12 methods and 52 properties.
RichTextToFlatStructureTransformer	Transforms rich text annotation content (XHTML with arbitrarily nested spans) into a flat structure where every leaf text node becomes a single <span style="."> with the fully-merged CSS from all ancestor elements.
ScreenAnnotation	The ScreenAnnotation class lets you add a screen annotation to a page by providing the page, rectangle, and media file, and exposes AnnotationType, Action, and Title properties.
SelectorRendition	A selector rendition (PDF §13.2.3.3) — chooses among alternative renditions.
SoundAnnotation	Class with 16 methods and 52 properties.
SoundData	Class with 5 properties.
SoundSampleData	SoundSampleData constructors allow specifying samplingRate alone or together with numberOfSoundChannels, bitsPerChannel, and SoundSampleDataEncodingFormat.
SquareAnnotation	The SquareAnnotation.Accept(visitor) method implements the visitor pattern, allowing custom processing of annotation objects.
SquigglyAnnotation	Squiggly text markup annotation.
StampAnnotation	Class with 16 methods and 53 properties.
StrikeOutAnnotation	StrikeOut text markup annotation.
TextAnnotation	Class with 16 methods and 54 properties.
TextMarkupAnnotation	Base class for the text-markup annotations (Highlight, Underline, StrikeOut, Squiggly) — those whose geometry is a set of QuadPoints over page text.
TextStyle	Bundled font / colour / alignment style applied to a free-text annotation's rich text.
TrimMarkAnnotation	Class with 8 methods and 48 properties.
UnderlineAnnotation	Underline text markup annotation.
WatermarkAnnotation	Represents a watermark annotation that can be added to a PDF page.
WidgetAnnotation	Class with 13 methods and 59 properties.
XYZExplicitDestination	XYZ explicit destination: display the page at position (left, top) with zoom factor.

Interfaces

Interface	Description
IAppointment	Marker interface for any object that can be stored in an outline item's Destination, a link annotation's Destination, Document.OpenAction, or a named-destination collection.

Enumerations

Enumeration	Description
ActivationEvent	Enum with 3 members.
AnnotationFlags	Annotation flags as defined in PDF spec Table 165.
AnnotationState	Review or marked-state of a markup annotation, as defined by PDF 32000 §12.5.6.3 (text annotations, /StateModel + /State entries).
AnnotationStateModel	Which state model a AnnotationState belongs to.
AnnotationType	Annotation subtype as defined in PDF spec Table 169.
BorderEffect	Border effect applied to annotations.
BorderStyle	Border style for annotations and fields.
CapStyle	Cap style used by ink strokes (free-hand drawings).
CaptionPosition	Caption-position within a LineAnnotation.
CaretSymbol	Caret-symbol style for CaretAnnotation.
ColorsOfCMYK	CMYK channel selector used by ColorBarAnnotation.
ContentType	Enum with 3 members.
ExplicitDestinationType	Explicit destination type, mirroring PDF 32000 §12.3.2.2 names.
FileIcon	Named-icon style for FileAttachmentAnnotation (/Name entry).
FractionStyle	How fractional values are rendered (decimal / fraction / round / truncate).
FreeTextIntent	Intent (sub-purpose) of a free-text annotation.
HighlightingMode	Highlighting mode for link annotations.
Justification	Justification of a free-text annotation's content.
LightingSchemeType	Lighting-scheme nominal type (PDF 32000-1 §13.6.4).
LineEnding	Line annotation ending styles (/LE entry elements).
LineIntent	Line annotation intents (/IT entry).
PDF3DActivation	How the embedded 3D model becomes active (PDF 32000-1 §13.6.2, AAS entry of the 3D activation dictionary).
PolyIntent	Intent of a polygon or polyline annotation (/IT entry).
PredefinedAction	Named viewer commands targeted by a NamedAction (PDF 32000 §12.6.4.11).
PrinterMarkCornerPosition	Corner a printer-mark annotation sits in (used by bleed-/trim-marks).
PrinterMarkSidePosition	Side a printer-mark annotation sits on.
PrinterMarksKind	The set of printer's-mark families AddPrinterMarks generates on a page (PDF 32000 pre-press marks).
RenderModeType	Render-mode nominal type (PDF 32000-1 §13.6.5).
ReplyType	Reply-relationship between a markup annotation and its InReplyTo target.
RichTextFontStyles	Rich-text run styles applied via Color).
SoundEncoding	Enum with 4 members.
SoundIcon	Enum with 2 members.
SoundSampleDataEncodingFormat	SoundSampleDataEncodingFormat enum defines the supported audio encodings: Raw, Signed, muLaw, and ALaw.
StampIcon	Named stamp-icon style for StampAnnotation (/Name entry, PDF 32000 §12.5.6.14).
TextAlignment	Horizontal text alignment for annotation text boxes.
TextIcon	Named-icon style for TextAnnotation (PDF 32000 §12.5.6.4 /Name entries).

Artifacts

Class	Description
Artifact	Represents a PDF artifact — a marked content sequence tagged as /Artifact (PDF 32000 §14.8.2.2).
ArtifactCollection	Collection of artifacts on a page.
BackgroundArtifact	Represents a background artifact (a coloured block or image painted behind page content).
HeaderArtifact	Represents a header artifact — a page-level running head tagged Artifact /Subtype /Header (PDF 32000 §14.8.2.2).
WatermarkArtifact	Represents a watermark artifact that can be added to a PDF page.

Enumerations

Enumeration	Description
ArtifactSubtype	Enumerates artifact subtypes.
ArtifactType	Enumerates artifact types as defined by PDF 32000 §14.8.2.2.

Collections

Class	Description
Collection	PDF Portfolio collection.
CollectionField	One column in a PDF Portfolio's collection schema (PDF spec §7.11.5 Table 75).
CollectionSchema	Schema of a PDF Portfolio collection (PDF spec §7.11.5 Table 74).
ImageCollection	Collection of image XObjects on a page.
ImageXObject	Represents an image XObject found in a PDF page's resources.
PageCollection	Collection of pages in a PDF document.
XImage	Image XObject wrapper that mirrors the Aspose.Pdf XImage public surface.
XImageCollection	Collection of image XObjects on a page, with XImage-typed accessors and editing helpers.

Enumerations

Enumeration	Description
CollectionFieldSubtype	Predefined collection field subtypes (PDF spec §7.11.5 Table 75).

Color

Class	Description
Color-Pdf	Represents a color value used in PDF documents.

Enumerations

Enumeration	Description
ColorSpace	Top-level device colour-space selector (Aspose.Pdf public surface).
ColorType	Represents the color type of a page.

Comparison

Class	Description
SideBySidePdfComparer	Compares the text of two pages or two documents and writes a result PDF showing both versions side by side with the changes highlighted (deletions on the left page, insertions on the right). Static Compare overloads target a file path or a stream.
SideBySideComparisonOptions	Options for the side-by-side comparer: whitespace ComparisonMode, AdditionalChangeMarks, ExcludeTables, per-side comparison and exclusion areas, and the DeleteColor / InsertColor markers.
SideBySideDocsComparisonResult	Result of a document-level comparison: HasChanges, plus per-page FirstDocChanges / SecondDocChanges highlights and the per-page FullChanges edit sequences.
SideBySidePagesComparisonResult	Result of a page-level comparison: HasChanges, the FirstPageChanges / SecondPageChanges highlights, and the FullChanges edit list.
EditContainer	A single highlighted change in a side-by-side result: its Id, the DiffOperation it came from, and the Rects it covers on the page.
GraphicalPdfComparer	Renders two pages and compares them pixel by pixel, with configurable Resolution, mark Color, and Threshold. Windows only — it hands back System.Drawing bitmaps.
ImagesDifference	The pixel difference of two rendered pages: raw Difference / Stride / Height, the SourceImage and GetDestinationImage(), and DifferenceToImage(). Windows only.
DiffOperation	A single edit produced when diffing two texts: an Operation (Equal / Delete / Insert) together with the run of text it applies to.
DiffUtils	Text helpers used by the diff engine: common prefix/suffix extraction and re-assembly of the source / destination text from a list of DiffOperations.
MergingOptimizer	Semantic clean-up pass: eliminates equalities that are no larger than the edits surrounding them (folding those short common runs back into the adjacent delete/insert), then re-merges the result into canonical form.
OperationsMerger	Merges a diff into its canonical minimal form: coalesces adjacent runs of the same operation, and for a mixed delete/insert run factors any common prefix into the preceding equality and any common suffix into the following equality.
OperationsSlideMerger	Shifts a single edit that is surrounded on both sides by equalities sideways to eliminate one of those equalities, canonicalising the diff.

Interfaces

Interface	Description
IDiffOptimizationOperation	A post-processing pass that normalises a diff — a mutable list of DiffOperations — in place, preserving the source and destination texts while producing a cleaner or more canonical sequence of edits.

Enumerations

Enumeration	Description
ComparisonMode	How the side-by-side comparer treats whitespace: Normal compares the extracted runs as-is, IgnoreSpaces compares only non-space characters, and ParseSpaces reconstructs inter-word spaces and line breaks from glyph geometry first.
EditOperationsOrder	When a delete and an insert are emitted for the same position, which one an optimizer places first in the resulting operation sequence.
Operation	The kind of edit a DiffOperation represents when diffing two texts: a run that is unchanged, deleted from the source, or inserted in the destination.

Content

Class	Description
BDC	BDC — Begin marked content with properties.
BI	BI — Begin inline-image object.
BMC	BMC — Begin marked-content sequence (no properties).
BT	BT — Begin text object.
BX	BX — Begin compatibility section.
BasicSetColorAndPatternOperator	Common base for SCN/scn (basic color or pattern).
BasicSetColorOperator	Common base for the rg/RG/g/G/k/K family.
BlockTextOperator	Common base for the BT / ET delimiters.
Clip	W — Set clipping path (nonzero winding rule).
ClosePath	h — Close subpath.
ClosePathEOFillStroke	b* — Close, fill, and stroke path (even-odd rule).
ClosePathFillStroke	b — Close, fill, and stroke path (nonzero winding rule).
ClosePathStroke	s — Close and stroke path.
ConcatenateMatrix	cm — Concatenate matrix to CTM.
ContentStreamBuilder	Builds PDF content stream bytes using the operator syntax from PDF32000 §8-9.
CurveTo	c — Append cubic Bézier curve with three control points.
CurveTo1	v — Append cubic Bézier curve; first control point is current point.
CurveTo2	y — Append cubic Bézier curve; second control point coincides with final point.
DP	DP — Designate marked-content point with property list.
Do	Do — Invoke named XObject.
EI	EI — End inline-image object.
EMC	EMC — End marked content.
EOClip	W* — Set clipping path (even-odd rule).
EOFill	f* — Fill path (even-odd rule).
EOFillStroke	B* — Fill and stroke path (even-odd rule).
ET	ET — End text object.
EX	EX — End compatibility section.
EndPath	n — End path without filling or stroking.
ExtGState	Represents an Extended Graphics State dictionary (PDF32000 §8.4.5).
ExtractedPath	Represents a complete path with its painting mode and color.
Fill	f — Fill path (nonzero winding rule).
FillStroke	B — Fill and stroke path (nonzero winding rule).
GRestore	Q — Restore graphics state.
GS	gs — Set parameters from named ExtGState resource.
GSave	q — Save graphics state.
GlyphPosition	One element of a TJ-style glyph-position array: a string with an optional preceding/following position adjustment (in 1/1000 text units).
GraphicsState	Tracks the PDF graphics state during content stream parsing (PDF32000 §8.4).
ID-Operators	ID — Begin image data (after the inline-image dictionary).
LineTo	l — Append straight line segment to (X, Y).
MP	MP — Designate marked-content point (no properties).
MoveTextPosition	Td — Move text position: translate text origin by (X, Y).
MoveTextPositionSetLeading	TD — Move text position and set leading: translate by (X, Y) and set leading to -Y.
MoveTo	m — Begin new subpath at (X, Y).
MoveToNextLine	T* — Move to next line using current leading.
MoveToNextLineShowText	' — Move to next line and show text.
ObsoleteFill	F — Fill path (deprecated; equivalent to f).
Operator-Operators	Back-compat alias for Operator kept so existing using Aspose.Pdf.Operators; code and the concrete operator subclasses (GSave, BT, ET, …) in this namespace continue to bind.
OperatorSelector	Visitor that filters content-stream operators by concrete type.
PathExtractor	Extracts vector paths from PDF page content streams.
PathSegment	Represents a segment of a path.
Re	re — Append rectangle (X, Y, Width, Height) as a complete subpath.
SelectFont	Tf — Select font and size.
SetAdvancedColor	scn — Set color (with optional pattern name) in current color space (non-stroking).
SetAdvancedColorStroke	SCN — Set color (with optional pattern name) in current color space (stroking).
SetCMYKColor	k — Set CMYK fill color.
SetCMYKColorStroke	K — Set CMYK stroke color.
SetCharWidth	d0 — Set glyph width in a Type 3 font.
SetCharWidthBoundingBox	d1 — Set glyph width and bounding box in a Type 3 font.
SetCharacterSpacing	Tc — Set character spacing.
SetColor	sc — Set color in current color space (non-stroking).
SetColorOperator	Common base for the SC/SCN/sc/scn family.
SetColorRenderingIntent	ri — Set color rendering intent.
SetColorSpace	cs — Set color space for non-stroking operations.
SetColorSpaceStroke	CS — Set color space for stroking operations.
SetColorStroke	SC — Set color in current color space (stroking).
SetDash	d — Set dash pattern.
SetFlat	i — Set flatness tolerance.
SetGlyphsPositionShowText	TJ — Show text with individual glyph positioning (array of strings and numeric adjustments).
SetGray	g — Set gray fill color.
SetGrayStroke	G — Set gray stroke color.
SetHorizontalTextScaling	Tz — Set horizontal text scaling.
SetLineCap	J — Set line cap style.
SetLineJoin	j — Set line join style.
SetLineWidth	w — Set line width.
SetMiterLimit	M — Set miter limit.
SetRGBColor	rg — Set RGB fill color.
SetRGBColorStroke	RG — Set RGB stroke color.
SetSpacingMoveToNextLineShowText	" — Set word/char spacing, move to next line, and show text.
SetTextLeading	TL — Set text leading.
SetTextMatrix	Tm — Set text matrix.
SetTextRenderingMode	Tr — Set text rendering mode.
SetTextRise	Ts — Set text rise.
SetWordSpacing	Tw — Set word spacing.
ShFill	sh — Paint shading specified by named resource.
ShowText	Tj — Show text string.
Stroke	S — Stroke path.
TextOperator	Common base for all text-related operators (BT/ET, Tx state, text-show, text-place).
TextPlaceOperator	Common base for text-positioning operators (Td, TD, T*, Tm).
TextShowOperator	Common base for text-showing operators (Tj, TJ, ', ").
TextStateOperator	Common base for text-state operators (Tc, Tw, Tz, TL, Tf, Tr, Ts).

Structs

Struct	Description
PathCommand	A single path construction command with coordinates.

Enumerations

Enumeration	Description
LineCap	Line cap style.
LineJoin	Line join style.
PathOp	Path construction operator type.
PathOperationType	Represents a type of path operation.
PathPaintMode	Represents a single path painting operation.

Converters

Class	Description
MarkdownConverterOptions	Options for PDF-to-Markdown conversion.
MdLoadOptions	Options for loading Markdown files as PDF documents.
PageSizeInfo	Page size configuration for document loading.
PdfToHtmlConverter	Converts PDF pages to HTML markup.
PdfToMarkdownConverter	Converts PDF pages to Markdown text.
PdfToSvgConverter	Converts PDF pages to SVG format.
PdfToTextConverter	Converts PDF pages to plain text.
SvgLoadOptions	Options for loading SVG files as PDF documents.
TxtLoadOptions	Options for loading a plain-text (.txt) file as a PDF document.

Enumerations

Enumeration	Description
ConversionEngines	Available conversion engines.

Devices

Class	Description
BmpDevice	Renders PDF document pages into BMP image format.
DocumentDevice	Abstract base for whole-document rendering devices.
GdiPlusPageRenderer	PDF page renderer that rasterizes through GDI+ (Graphics).
GifDevice	Renders PDF document pages into GIF image format.
ImageDevice	Abstract base class for image rendering devices (PNG, JPEG, BMP, TIFF).
ImagePageDevice	Default PageDevice that delegates to any ImageDevice — PngDevice / JpegDevice / BmpDevice / TiffDevice.
IndexBitmapConverter	Abstract base class for converting rendered images to indexed (1/4/8bpp) bitmaps.
JpegDevice	Renders PDF document pages into JPEG image format.
Margins	Page margins in points for TIFF rendering.
PageDevice	Abstract base for single-page rendering devices.
PageSize-Devices	Represents a physical page size in points.
PdfDocumentDevice	Default DocumentDevice implementation that saves the document as a PDF (Document.Save round-trip).
PngDevice	Renders PDF document pages into PNG image format.
RgbaBuffer	Raw RGBA pixel buffer returned by a IPageRenderer.
SoftwarePageRenderer	Built-in software PDF page renderer.
SvgDevice	Converts a PDF page to SVG markup.
TextDevice	Extracts text from PDF pages.
TiffDevice	Renders PDF document pages into TIFF image format.
TiffSettings	Settings for TIFF image generation (color depth, compression).

Interfaces

Interface	Description
IPageRenderer	Renders a PDF page to an RGBA pixel buffer.

Enumerations

Enumeration	Description
ColorDepth	Color depth options for TIFF encoding.
CompressionType	TIFF compression algorithm options.
FormPresentationMode	How form fields are rendered (canonical Production / Editor split).
PageCoordinateType	Which page-box the rendered image extents come from.
ShapeType	Shape type for TIFF rendering.

Drawing

Class	Description
Arc	An arc shape (portion of an ellipse).
Circle	A circle shape.
Color-Drawing	Color for drawing shapes.
Curve	A Bézier curve shape.
DrawingPath	A path shape composed of move, line, and curve segments.
DrawingRectangle	A rectangle shape.
Ellipse	An ellipse shape.
GradientAxialShading	Defines a linear (axial) gradient between two colors for use as a fill pattern.
Graph	A graph container that holds drawable shapes and renders them to a content stream.
Line	A line shape.
PatternColorSpace	Pattern colour-space marker (Aspose.Pdf public surface).
Point-Drawing	A 2D point (x, y).
Polygon	A polygon shape (closed path with arbitrary vertices).
Rectangle-Drawing	A rectangle shape in the Drawing namespace (distinct from Aspose.Pdf.Rectangle which is a page rectangle).
Shape	Base class for drawable shapes.

Enumerations

Enumeration	Description
ImageFormat	Specifies the encoding format of an image.

Enums

Class	Description
Id	Pair of byte strings that make up the /ID array in the PDF trailer.

Enumerations

Enumeration	Description
Direction	Predominant text-flow direction recorded in the viewer-preferences dictionary.
ExtendedBoolean	A tri-state Boolean — True/False plus an Undefined sentinel used at deserialization time when a value isn't carried on the PDF dictionary entry.
FieldValueType	Logical value type carried by a CollectionField.
HorizontalAlignment	Describes horizontal alignment.
PageLayout	Page-layout entry written to the catalog (PDF32000 Table 28).
PageMode	Page-mode entry written to the catalog (PDF32000 Table 28).
PdfVersion	PDF specification version targeted by the document header.
PrintDuplex	Print-duplex value recorded in viewer preferences (PDF32000 Table 150).
VerticalAlignment	Describes vertical alignment.

Exceptions

Class	Description
CrashReportOptions	Configures crash-report emission for GenerateCrashReport.
DeprecatedFeatureException	Thrown when a mechanism ISO 32000-2 retires is used on a PDF 2.0 document — RC4 under the 2.0 encryption flag, a legacy security handler, or the raw-RSA / enveloping PKCS#7 signature subfilters.
FontNotFoundException	Thrown when a requested font cannot be located (no system font with that name, no matching custom-font source, etc.).
IncorrectFontUsageException	Thrown during text extraction when the content stream issues a text-showing operator (Tj/TJ/'/") while no font is set in the current graphics state — i.e.
InvalidFormTypeOperationException	Thrown when an operation is attempted on the wrong form type (e.g.
InvalidPasswordException	Thrown when a password-protected operation is attempted without supplying a valid password (e.g.
InvalidPdfFileFormatException	Thrown when a stream cannot be opened as a PDF (bad header, truncated file, or otherwise unrecognisable as PDF).
PdfException	Represents errors that occur during PDF application execution.
PdfExceptionMessages	Centralised message strings surfaced by the library's exceptions and security diagnostics.
PdfTextDecodingException	Thrown when text content cannot be decoded — e.g.
UnsupportedFontTypeException	Thrown when a file cannot be opened as a font because its format is not a supported font program (e.g.
ValidationIssue	Represents a validation issue found in a PDF document.

Facades

Class	Description
AlignmentType	Horizontal-alignment selector for legacy facade APIs (e.g.
AutoFiller	Repeatedly stamps a template PDF with rows from a DataTable: for each row, fills the form fields whose names match column names, flattens (except those listed in UnFlattenFields), and appends the resulting pages to the output.
BDCProperties	Properties for a BDC / DP marked-content operator (/MCID and /Lang).
Bookmark	A single bookmark extracted from a document's outline tree by ExtractBookmarks().
Bookmarks	An ordered, indexable collection of Bookmark entries returned by ExtractBookmarks().
ContentsResizeParameters	Parameters for ResizeContents describing margins, content size, and whether the page media box should change to match.
ContentsResizeValue	Represents a content-resize value.
CorruptedItem	One file the Concatenate path could not parse — recorded only when CorruptedFileAction is set to skip-and-continue.
DocumentPrivilege	Represents document access permissions (P value in encryption dictionary).
FontColor	Represents a font color using RGB components.
Form-Facades	Facade for form field manipulation including XML import/export.
FormDataConverter	Bridges PDF form-data formats (FDF / XFDF / XML) with DataTable and direct stream-to-stream transforms.
FormEditor	Facade for form operations: fill fields, flatten forms, import/export data.
FormFieldFacade	Represents the visual appearance attributes of a form field.
FormImportResult	Per-field result of a form-data import operation.
FormattedText	Represents formatted text used in stamp and mend operations.
FormattedTextFont	Represents a font reference returned by FormattedText.getFont().
LineInfo	Line drawing parameters for PdfContentEditor.DrawCurve.
PageBreak	Describes a single horizontal cut on a source page: PageNumber (1-based) identifies the page in the source document, Position the PDF y-coordinate where the page is split.
PdfAnnotationEditor	Facade for annotation manipulation: import/export XFDF, delete, flatten, redact.
PdfBookmarkEditor	Facade for bookmark (outline) manipulation: create, extract, delete bookmarks.
PdfContentEditor	Facade for content-level editing: text replacement, link creation, image operations.
PdfConverter	Facade for converting PDF pages to images.
PdfExtractor	Facade for extracting text and images from a PDF document.
PdfFileEditor	Real-only additions to PdfFileEditor: exception-handling state, Try* wrappers around the existing working methods, and MemoryStream/file overloads for SplitToBulks/SplitToPages that wrap the real byte[] implementations already present in PdfFileEditor.cs.
PdfFileInfo	Facade for accessing PDF document metadata and properties.
PdfFileMend	Facade for adding text and images to existing PDF documents.
PdfFileSecurity	Facade for encrypting, decrypting, and changing passwords on PDF files.
PdfFileSignature	Facade for signing and reading digital signatures in PDF documents.
PdfFileStamp	Facade for adding stamps, page numbers, headers, footers, and watermarks.
PdfJavaScriptStripper	Removes all JavaScript from a PDF document.
PdfPageEditor	Facade for page-level editing: rotation, resizing, margin adjustment, and page box manipulation (CropBox, TrimBox, BleedBox, ArtBox).
PdfPrintPageInfo	Class with 1 property.
PdfViewer	Façade for viewing / printing a PDF document.
PdfXmpMetadata	Dictionary-style facade over a PDF document's XMP metadata stream.
RenderingOptions-Facades	Rendering options used by PdfConverter and other facade classes.
ReplaceTextStrategy	Configures how ReplaceText(string, string) matches and substitutes text.
SignatureName	Identifies a signature field by both its partial name (Name) and full hierarchical name (FullName), and reports whether the field currently carries a signature value via HasSignature.
Stamp-Facades	Represents a stamp to be applied via PdfFileStamp facade.
StampInfo	Contains information about a stamp on a page.
TextProperties	Text-display properties consumed by the *TextOperator family.
VerticalAlignmentType	Vertical-alignment selector for legacy facade APIs (e.g.
ViewerPreference	Bag of const int bit-flags describing viewer preferences (page mode, page layout, fullscreen behaviour, duplex, print scaling, reading direction).

Interfaces

Interface	Description
IFacade	Interface with 5 methods.
ISaveableFacade	Interface with 5 methods.

Enumerations

Enumeration	Description
Algorithm	Encryption algorithm family used by PdfFileSecurity.
AutoRotateMode	Auto-rotation behaviour for the PDF viewer.
BlendingColorSpace	Blend-mode colour-space hint passed to a Stamp.
ConcatenateCorruptedFileAction	How the facade reacts to corrupted input during Concatenate.
DataType	Form-data source / destination kind consumed by FormDataConverter.
DefaultMetadataProperties	Well-known XMP-basic-schema property keys exposed by PdfXmpMetadata as a typed alternative to raw "xmp:<name>" strings.
EncodingType	Encoding type enumeration for FormattedText.
ExtractImageMode	Image extraction mode — matches docs.aspose.com Aspose.Pdf.ExtractImageMode.
ExtractTextMode	Text extraction mode — matches docs.aspose.com "Pure" (0) / "Raw" (1).
FieldType-Facades	The type of an AcroForm field, as used by AddField and related facade operations.
FontStyle	Font style enumeration for FormattedText.
ImageMergeMode	Layout strategy used by MergeImages when combining multiple input images into a single output image.
ImportStatus	Outcome of importing a single field's value.
KeySize	Key strength selector paired with Algorithm to pick the concrete RC4/AES variant used by PdfFileSecurity.
NoCharacterAction-Facades	What to do when the replacement font lacks a glyph for a character.
PdfConverterImageFormat	Image format for PdfConverter output.
PositioningMode	Text positioning mode for PdfFileMend.
PropertyFlag	Attribute flags applied to a form field via SetFieldAttribute.
Scope-Facades	How many matches to replace per call.
StampType	Stamp kind exposed by StampInfo.
SubmitFormFlag	Format of the data posted by a Submit form action — set per field via SetSubmitFlag.
WordWrapMode-Facades	Word wrap mode for PdfFileMend text operations.

Forms

Class	Description
AcroFormData	Form-level AcroForm dictionary data surfaced by the form JSON export.
AppearanceEntry	One state of a widget appearance variant (the body of an /AP/N, AP/D, or /AP/R entry).
ButtonField	Push-button form field (FT=Btn with Pushbutton flag set).
CheckboxField	Class with 26 methods and 84 properties.
ChoiceField	Class with 25 methods and 89 properties.
ComboBoxField	Combo box (drop-down) form field — a ChoiceField with the Combo flag set.
DefaultResourcesData	Form-level default resources (/DR) surfaced by the form JSON export.
DocMDPSignature	Pairs a Signature (which carries the signing certificate) with the DocMDPAccessPermissions level a certifying signature will impose.
ExportFieldsToJsonOptions	Options passed to ExportToJson.
Field	Represents a form field.
FieldExportingData	Data-transfer object describing a single form field (or the form-level AcroForm dictionary) as produced by the form JSON export.
FieldSerializationResult	Per-field outcome of an ExportToJson or ImportFromJson call.
FlattenSettings	Settings for Flatten(FlattenSettings).
Form-Forms	Represents the interactive form (AcroForm) of a PDF document.
FormFieldBuilder	Creates new interactive form fields and adds them to a PDF document.
IconFit	PDF Annotation Handler "IF" entry — icon-fit dictionary for push-button widgets.
ListBoxField	List box form field — a ChoiceField without the Combo flag.
Option	Class represents option of choice field.
OptionCollection	Mutable collection of Option values backed by the owning ChoiceField's /Opt entry.
PKCS1	Class with 7 methods and 14 properties.
PKCS7	Class with 6 methods and 14 properties.
PKCS7Detached	A detached PKCS#7 (CMS) signature configuration.
RadioButtonField	Class with 27 methods and 95 properties.
RadioButtonGroup	A logical radio-button group — a set of mutually exclusive options sharing the same field name in the AcroForm hierarchy.
RadioButtonOption	A single option within a radio button group.
RadioButtonOptionField	One option of a RadioButtonField.
RichTextBoxField	A Tx form field that carries the rich-text flag (bit 26 of /Ff).
Signature	Represents a digital signature in a PDF document.
SignatureCustomAppearance	Visual-layout knobs for a signature's appearance stream — font, size, padding and which signer metadata strings are rendered inside the widget annotation.
SignatureField	SignatureField.Sign(signature) applies a digital signature to a form field, and Flatten() can make the signature appearance permanent in the document.
TextBoxField	The TextBoxField class lets developers create AcroForm text fields with multiple constructors and supports adding barcodes and images to the field.
XFA	XmlNode-based accessor for the document's XFA packets (template / datasets / config / form / xdp).
XfaAccessor	Provides indexer access to XFA field values by path.
XfaField	Represents a single field of an XFA form addressed by its template SOM path (e.g.

Enumerations

Enumeration	Description
BoxShape	Outer shape of a checkbox / radio-button widget border.
BoxStyle	Visual style of the checkbox glyph (/MK /CA mapping).
DocMDPAccessPermissions	/DocMDP /TransformParams /P access-permission levels per PDF 32000-1 §12.8.2.2.
FieldSerializationStatus	Outcome of serializing a single form field through ExportToJson or ImportFromJson.
FieldType-Forms	The type of a form field.
FormType	Represents the type of a PDF form.
IconCaptionPosition	PDF Annotation Handler "TP" entry — caption / icon layout for push-button widgets.
ScalingMode	How a button icon is scaled to fit its rectangle (/MK /IF /SW).
ScalingReason	When to scale the icon to fit its rectangle (/MK /IF /S).
SignDependentElementsRenderingModes	How widgets dependent on signature appearance are rendered when the form is converted.
SubjectNameElements	X.500 distinguished-name components rendered inside the visible signature appearance when UseDigitalSubjectFormat is set.

Functions

Class	Description
ExponentialFunction	Exponential interpolation function (§7.10.3).
PdfFunction	Abstract base for all PDF function types.
PostScriptEvaluator	PostScript calculator evaluator for Type 4 PDF functions (PDF32000 §7.10.5).
PostScriptFunction	PostScript calculator function (§7.10.5).
SampledFunction	Sampled function (§7.10.2): lookup table with linear interpolation.
StitchingFunction	Stitching function (§7.10.4): combines sub-functions over sub-domains.

Generator

Class	Description
BaseParagraph	Base class for paragraph-level DOM content (text fragments, tables, images, header/footer fragments, floating boxes).
BorderInfo	Represents border information for table cells and rows.
Cell	Represents a cell in a table row.
Cells	A collection of cells in a row.
ColumnInfo	ColumnInfo stores table layout details, exposing ColumnWidths, ColumnSpacing, and ColumnCount properties for precise column sizing.
FileHyperlink	Hyperlink that launches an external file (e.g.
FloatingBox	Represents a floating box that can be positioned absolutely or flowed on a page.
GraphInfo	Stroke / fill settings for drawable shapes and table-cell borders.
HeaderFooter	Represents a header or footer that can be applied to PDF pages.
Heading	Represents a TOC heading entry that links to a destination page.
Hyperlink	Base type for hyperlinks attached to text fragments or annotations.
LevelFormat	Per-heading-level TOC formatting descriptor (line-dash style, margins, indent, text state).
LocalHyperlink	Hyperlink that jumps to another paragraph or page in the same document.
MarginInfo	Represents margin information for page elements.
Note	A footnote or endnote attached to a TextFragment.
Paragraphs	Container for paragraph-level content (text fragments, tables, images, header/footer fragments, etc.) attached to a Page, Cell, HeaderFooter or FloatingBox.
Row	Represents a row in a table.
Rows	A collection of rows in a table.
Table	Represents a table that can be added to a PDF page.
TocInfo	Table of contents information for a page.
WebHyperlink	Hyperlink that opens an external URL.

Enumerations

Enumeration	Description
BorderCornerStyle	Corner-rounding style for a Table's border box.
BorderSide	Specifies which sides of a border to draw.
ColumnAdjustment	How a Table sizes its columns (API parity).
ParagraphPositioningMode	How Left / Top are interpreted.
TableBroken	TableBroken enum indicates how a table is split across pages, with values None, Vertical, VerticalInSamePage, and IsInNextPage.

Geometry

Class	Description
Matrix	Represents a 3x3 transformation matrix [a b 0; c d 0; e f 1].
Matrix3D	4×3 affine 3D matrix (Aspose.Pdf shape for PDF 3D camera positioning).
PageSize-Pdf	Standard page size constants (dimensions in points, portrait orientation).
Point-Pdf	Represents a point in 2D space.
Point3D	Represents a point in 3D space (used by 3D annotations).
Rectangle-Pdf	Represents a rectangle defined by lower-left and upper-right coordinates (PDF user-space convention: Y increases upward).

Groupprocessor

Struct	Description
ObjectKey	Identifies a PDF indirect object by its object number and generation number.

Helpers

Class	Description
BoundsCheckableList	A list of T that optionally enforces container bounds on insertion.
OptimizedMemoryStream	A growable in-memory stream that can exceed the 2 GB single-array limit of MemoryStream by storing data in fixed-size chunks.
PolygonsHelper	Polygon and rectangle geometry utilities — point/polygon containment, segment hit-testing and rectangle/polygon classification.

Enumerations

Enumeration	Description
BoundsCheckMode	How a BoundsCheckableList{T} reacts when an item lies outside its container.
RectanglePosition	Position of a rectangle relative to a polygon, as returned by GetRectanglePositionRelativePolygon.

HTML

Class	Description
CssSavingInfo	Context passed to a CssSavingStrategy callback.
CssUrlRequestInfo	Context passed to a CssUrlMakingStrategy callback.
HtmlFragment	Represents an HTML content fragment that can be added to PDF pages via HeaderFooter.Paragraphs or Page.Paragraphs.
HtmlImageSavingInfo	Context passed to a per-image saving callback.
HtmlLoadOptions	Options for loading HTML content into PDF.
HtmlPageMarkupSavingInfo	Context passed to a HtmlPageMarkupSavingStrategy callback.
HtmlSaveOptions	Options for saving a PDF document as HTML.

Enumerations

Enumeration	Description
AntialiasingProcessingType	Antialiasing pass applied to the resulting HTML.
FontEncodingRules	Backing-byte enum: the Aspose.Pdf reflection signature is byte-typed.
FontSavingModes	How fonts are emitted into the output HTML.
HtmlDocumentType	HTML document flavour produced by HtmlSaveOptions.
HtmlImageType	Image type produced for embedded raster content.
HtmlMarkupGenerationModes	Granularity of HTML markup produced.
HtmlMediaType	Specifies the media type for HTML rendering.
HtmlPageLayoutOption	How the generated PDF page layout reacts to wide HTML content.
ImageParentTypes	Container element that hosts an image.
LettersPositioningMethods	How letter positions are encoded in the output CSS.
PartsEmbeddingModes	Whether and how secondary parts (CSS / images / fonts) are embedded.
RasterImagesSavingModes	How raster images are saved alongside the HTML.

Interop

Class	Description
BitmapInfo	Class with 2 methods and 4 properties.

Interfaces

Interface	Description
IIndexBitmapConverter	Interface with 3 methods.

Enumerations

Enumeration	Description
PixelFormat	Enum with 6 members.

Io

Class	Description
ZDeflaterOutputStream	zlib (RFC 1950) deflating output stream — a public helper matching the Aspose.Pdf surface.
ZInflaterInputStream	zlib (RFC 1950) inflating input stream — a public helper matching the Aspose.Pdf surface.

Logicalstructure

Class	Description
AnnotElement	Class with 11 methods and 13 properties.
ArtElement	Class with 11 methods and 13 properties.
AttributeName	A typed value for a standard attribute name (the /Name-valued entries in an attribute object, e.g.
BibEntryElement	Class with 11 methods and 13 properties.
BlockQuoteElement	Class with 11 methods and 13 properties.
CaptionElement	Class with 11 methods and 13 properties.
CodeElement	Class with 11 methods and 13 properties.
DivElement	Class with 11 methods and 13 properties.
DocumentElement	The document root structure element (/S Document).
Element-LogicalStructure	Common base for nodes in the logical-structure tree.
ElementList	An ordered list of structure elements, as returned by ChildElements.
FigureElement-LogicalStructure	FigureElement also offers AdjustPosition(settings) to reposition the figure according to layout settings.
FormElement	Class with 11 methods and 13 properties.
FormulaElement	Class with 12 methods and 17 properties.
HeaderElement	Class with 11 methods and 13 properties.
IllustrationElement	Abstract base for illustration-kind structure elements (Figure, Formula).
IndexElement	Class with 11 methods and 13 properties.
LinkElement	Class with 11 methods and 15 properties.
ListElement	Class with 11 methods and 13 properties.
ListLBodyElement	Class with 11 methods and 13 properties.
ListLIElement	Class with 11 methods and 13 properties.
ListLblElement	Class with 11 methods and 13 properties.
MCRElement	A marked-content reference leaf (role "MCR") emitted by the auto-tagger to mark where a structure element's page content lives.
NonStructElement	NonStructElement.SetTag(tag) assigns a custom tag to a non‑structural element, influencing its identification in the PDF structure tree.
NoteElement	Class with 11 methods and 13 properties.
OBJRElement	An object reference (role "OBJR") — links a structure element to a PDF object on a page (typically an annotation, e.g.
ParagraphElement	ParagraphElement provides methods to modify its text, tag, ID, and hierarchical position within a PDF structure.
PartElement	Class with 11 methods and 13 properties.
PrivateElement	Class with 11 methods and 13 properties.
QuoteElement	Class with 11 methods and 13 properties.
ReferenceElement	Class with 11 methods and 13 properties.
RubyElement	Class with 11 methods and 13 properties.
SectElement	SectElement provides methods such as AppendChild, SetTag, SetText, and Remove to build and manipulate structural elements within a PDF document.
SpanElement	SpanElement methods such as AppendChild, SetTag, SetText, SetId, AdjustPosition, and ChangeParentElement let developers build and manipulate structured PDF content.
StructTreeRootElement	The /StructTreeRoot wrapper at the top of the logical- structure tree.
StructureAttribute	A single tagged-PDF structure attribute (key plus one typed value).
StructureAttributes	An owner-scoped set of StructureAttribute objects attached to a structure element (one PDF attribute dictionary with a fixed /O owner).
StructureElement	Base class for tagged-PDF logical-structure elements.
StructureElementAttributes	The attribute manager exposed by Attributes.
StructureTextState	Text-state snapshot used to format inline structure-element runs.
StructureType	A structure-type role (the /S entry value), exposed via S.
TOCElement	Class with 11 methods and 13 properties.
TOCIElement	Class with 11 methods and 13 properties.
TableElement	Class with 14 methods and 31 properties.
TableTBodyElement	Class with 12 methods and 13 properties.
TableTDElement	TableTDElement.ColSpan and RowSpan properties allow a cell to span multiple columns or rows within a Table.
TableTFootElement	Class with 12 methods and 13 properties.
TableTHElement	Class with 11 methods and 23 properties.
TableTHeadElement	Class with 12 methods and 13 properties.
TableTRElement	Class with 13 methods and 23 properties.
WarichuElement	Class with 11 methods and 13 properties.

Interfaces

Interface	Description
ITextElement	A structure element that can carry inline text content (written to the element's /ActualText entry).

Enumerations

Enumeration	Description
AttributeKey	Standard tagged-PDF attribute keys (ISO 32000-1 §14.8.5).
AttributeOwnerStandard	Standard owners of a tagged-PDF attribute set (the /O entry of an attribute object, ISO 32000-1 Table 348).

Navigation

Class	Description
DestinationArray	Opaque wrapper around a PDF destination array, created by NamedDestination factory methods.
DestinationCollection	Named-destination collection exposed as IEnumerable<KeyValuePair<string, object>> for Aspose.Pdf parity.
NamedDestination	Represents a named destination in the document (PDF32000 §12.3.2.3).
NamedDestinationCollection	Collection of named destinations in the document.
OutlineBuilder	Builder for creating bookmarks (outlines) programmatically.
OutlineCollection	Class with 11 methods and 8 properties.
OutlineItem	Represents a bookmark (outline item) in the document outline hierarchy.
OutlineItemBuilder	Builder for a single outline item with fluent API.
OutlineItemCollection	The document outline (bookmark tree).
Outlines	Document-level bookmark (outline) collection.
PageLabel	Represents a page label range.
PageLabelBuilder	Builder for creating page labels on a document.
PageLabelCollection	Collection of page label ranges from the /PageLabels number tree.

Enumerations

Enumeration	Description
NumberingStyle	Numbering style for page labels.

Optimization

Class	Description
AutoTaggingSettings	Settings controlling automatic structure-tree generation during conversion.
FontEmbeddingOptions	Font-embedding behaviour during conversion.
HeadingLevels	Heading-level recognition tuning for AutoTaggingSettings.
ImageCompressionOptions	Image-compression sub-options for OptimizationOptions.
OptimizationOptions-Optimization	Class which describes document optimization algorithm.
PdfANonSpecificationFlags	PDF/A non-spec compliance toggles.
PdfASymbolicFontEncodingStrategy	Strategy for re-encoding symbolic fonts during PDF/A conversion.
PdfFormatConversionOptions	Options for converting a PDF document to a specific PDF/A conformance level.
QueueItem	One entry in the priority queue — names a single (platformID, platformSpecificID) cmap subtable.
RgbToDeviceGrayConversionStrategy	Converts all RGB color operators and image color spaces on a page to DeviceGray.
ToUnicodeProcessingRules	Rules applied when generating ToUnicode CMaps during conversion.

Enumerations

Enumeration	Description
CMapEncodingTableType	OpenType cmap subtable selector.
ConvertErrorAction	Action to take when a conversion error is found.
ConvertSoftMaskAction	Soft-mask handling strategy during PDF/A conversion.
ConvertTransparencyAction	Action to take when transparency is encountered during PDF/A conversion.
HeadingRecognitionStrategy	Algorithm used to detect headings during auto-tagging.
ImageCompressionVersion	Strategy version for image compression.
ImageEncoding	How image streams are re-encoded during optimization.
PdfFormat	PDF format/conformance level for validation and conversion.
PuaProcessingStrategy	Strategy for processing Private-Use-Area Unicode characters.
RemoveFontsStrategy	Strategy for removing or excluding fonts during conversion.
SegmentAlignStrategy	Strategy for collapsing adjacent text segments during PDF/A conversion.

Options

Class	Description
BorderPartStyle	Class with 1 method and 1 property.
CompositingParameters	Image-blending parameters consumed by Stream, int, float, float, float, float, CompositingParameters).
LayerCollection	Represents the collection of layers on a specific page.
LayerEntry	Represents a layer being built by OptionalContentBuilder.
LoadOptions	Class with 4 properties.
MarginPartStyle	One side of a MarginInfo: either a fixed PDF-point value or an auto-fit hint.
OptionalContentBuilder	Creates optional content groups (layers) in a PDF document.
OptionalContentGroup	Represents an Optional Content Group (layer) in a PDF document.
OptionalContentProperties	Collection of Optional Content Groups (layers) in a document.
OutputIntent	Represents a PDF OutputIntent entry (PDF32000 §14.11.5).
OutputIntents	Collection of OutputIntent entries on the document catalog's /OutputIntents array.
PdfSaveOptions	Class with 8 properties.
ProgressEventHandlerInfo	Class in the PDF .NET API.
RenderingOptions-Pdf	Rendering options used by the page-to-image converters (PngDevice, JpegDevice, PdfConverter, …).
ResourceLoadingResult	Class with 1 method and 1 property.
ResourceSavingInfo	Class with 1 property.
SaveOptions	The SaveOptions class exposes properties such as SaveFormat, CloseResponse, and WarningHandler to control PDF saving behavior.
SvgImageSavingInfo	Class with 2 properties.
SvgSaveOptions	SvgSaveOptions provides properties such as SaveFormat to control how a PDF is saved as SVG.
UnifiedSaveOptions	Class with 7 properties.
ViewerPreferences	Represents the document's viewer preferences (PDF32000 §12.2).

Enumerations

Enumeration	Description
BlendMode	PDF blend modes (Table 136 of PDF 32000-1:2008).
DefaultState	Default visibility state of an Optional Content Group (layer).
HtmlBorderLineType	Enum with 9 members.
LoadFormat	Source format selector used by LoadOptions.
NodeLevelResourceType	NodeLevelResourceType enum distinguishes between Font and Image resources when working with structural elements.
PageLayoutMode	Page layout mode for the document (PDF32000 §12.2, Table 28).
PageModeValue	Page mode specifying how the document should be displayed on opening (PDF32000 §12.2, Table 28).
ProgressEventType	Conversion-progress milestones reported via EventType.
SaveFormat	Save format enumeration.
SvgExternalImageType	Image format used by the SVG embedded-image saver.

Printing

Class	Description
CustomPrintEventArgs	Event args raised by PdfViewer.CustomPrint.
PageSettings	Per-page print settings (paper size / orientation / margins).
PaperSize	The PaperSize class lets developers define custom page dimensions by specifying a name, width, and height.
PdfQueryPageSettingsEventArgs	Event args supplied to PdfViewer.PdfQueryPageSettings.
PrinterSettings	Printer-side settings (printer name, copies, range).
StartEndPageEventArgs	Event args raised by PdfViewer.StartPage / EndPage.

Security

Class	Description
BitString	A variable-length bit string supporting bitwise operations, concatenation, substring extraction, and conversion to/from bytes and hex.
CertificateEncryptionOptions	Bundles the public certificate used to encrypt a document and the private-key store needed to decrypt it.
EncryptionInfo	Information about a document's encryption.
EncryptionParameters	Parameters parsed from the document's /Encrypt dictionary and passed to Initialize when a custom security handler takes over for an alternative /Filter.
HashAlgorithmFactory	Creates a HashAlgorithm for a DigestHashAlgorithm.
MathExtensions	Small integer math helpers shared by the security primitives.
PdfCertificate	Represents a certificate + private key for PDF signing.
PdfSigner	Signs PDF documents with X.509 certificates using PKCS#7/CMS detached signatures.
Sha3_256	SHA3-256 (FIPS 202) — own Keccak implementation.
Sha3_384	SHA3-384 (FIPS 202) — own Keccak implementation.
Sha3_512	SHA3-512 (FIPS 202) — own Keccak implementation.
SignatureAlgorithmInfo	Algorithm + digest + envelope-standard triple extracted from a PDF signature value.
SignatureAppearance	Defines the visual appearance for a digital signature annotation.
SignatureOptions	Options for signing a PDF document.
ValidationOptions	Tunes the verification policy used by Verify(SignatureName, ValidationOptions, out ValidationResult).
ValidationResult	Verification outcome produced by Verify(SignatureName, ValidationOptions, out ValidationResult).

Interfaces

Interface	Description
ICustomSecurityHandler	Pluggable custom security handler — implement this to handle non-Standard /Filter entries (e.g.

Enumerations

Enumeration	Description
CryptoAlgorithm	PDF encryption algorithm.
CryptographicStandard	Cryptographic envelope standard reported by a PDF signature SubFilter entry.
DigestHashAlgorithm	Digest hash algorithm used by a PDF signature (PKCS#7 messageDigest attribute).
SignatureAlgorithmType	Signing-algorithm family extracted from a signature's PKCS#7 signatureAlgorithm OID.
ValidationMethod	Revocation-check protocol selector used by ValidationMethod.
ValidationMode	How aggressively VerifySignature(string, ValidationOptions, out ValidationResult) reports problems.
ValidationStatus	Outcome categories reported by Status.

Shading

Class	Description
AxialShading	Axial (linear) shading (Type 2, §8.7.4.3).
CoonsPatchShading	Coons patch mesh (Type 6, §8.7.4.5.7).
FreeFormGouraudShading	Free-form Gouraud-shaded triangle mesh (Type 4, §8.7.4.5.5).
FunctionBasedShading	Function-based shading (Type 1, §8.7.4.2).
LatticeFormGouraudShading	Lattice-form Gouraud-shaded triangle mesh (Type 5, §8.7.4.5.6).
Pattern	Abstract base for all PDF pattern types.
RadialShading	Radial (circular) shading (Type 3, §8.7.4.4).
ShadingBase	Abstract base for all PDF shading types (§8.7.4.1).
ShadingPattern	Shading pattern (PatternType 2, §8.7.3.2): smooth gradient.
TensorPatchShading	Tensor-product patch mesh (Type 7, §8.7.4.5.8).
TilingPattern	Tiling pattern (PatternType 1, §8.7.3.1): repeating tile.

Enumerations

Enumeration	Description
ShadingType	Shading type — /ShadingType entry.

Stamps

Class	Description
PageNumberStamp	A stamp that adds page numbers to PDF pages.
PdfPageStamp	Stamps the content of one PDF page onto another page.
Stamp-Stamps	Base class for stamps that can be applied to PDF pages.
TextStamp-Stamps	A text stamp that can be applied to PDF pages.
WatermarkStamp	A watermark stamp that draws diagonal text across the page.

Structure

Class	Description
Element-Structure	A node in a PDF's logical-structure tree (the /StructTreeRoot /K subtree, plus their /K descendants).
ElementCollection	A live, mutable collection of structure elements held under a parent's /K array.
FigureElement-Structure	A figure structure element (/S = "Figure") that wraps a raster or vector picture.
RootElement	Top-level wrapper for the PDF /StructTreeRoot dictionary.
StructElement	A generic structure element (anything other than the recognised typed subclasses).
TextElement	A text-bearing structure element (Span / P / Quote / Note / Reference / BibEntry).

Tagged

Class	Description
MarkedContentInfo	Information about a marked content sequence, used to wrap content in BDC/EMC operators.
PositionSettings	Layout/position settings for a tagged structure element, passed to AdjustPosition.
StructTreeElement	Read-only view of a single structure element in a tagged document's structure tree: its role, accessibility text, attributes, marked-content references, and child elements.
StructTreeRoot	Read-only view of a tagged document's structure-tree root (/StructTreeRoot).
StructureElementBuilder	Builder for creating a structure element with children and marked content.
StructureTreeBuilder	Builds a logical structure tree for a tagged PDF document.
TaggedContent	Provides access to tagged PDF metadata (title, language) and the logical structure tree.
TaggedException	Exception thrown when a tagged PDF structure operation violates PDF spec constraints.

Interfaces

Interface	Description
ITaggedContent	The author-facing surface for a tagged PDF document.

Text

Class	Description
AbsorbedCell	Represents a cell in an absorbed table.
AbsorbedRow	Represents a row in an absorbed table.
AbsorbedTable	Represents a table detected on a PDF page.
CharInfo	Per-character layout information (glyph rectangle + page position).
CharInfoCollection	Collection of CharInfo entries — supports the public surface used by TextSegment.Characters but stays empty by default.
CustomFontSubstitutionBase	Class with 1 method.
ExternalFontCache	Manages the set of folders searched for external (non-embedded) TrueType/OpenType faces during rendering and conversion.
FileFontSource	A font source backed by a single font file on disk.
FolderFontSource	A font source that searches fonts in a specific directory.
Font	Type alias for FontInfo, matching the Font class name.
FontAbsorber	Collects all fonts used in a PDF document or a single page.
FontCollection	Collection of fonts referenced by a page.
FontData	Represents a font with its name and type.
FontEmbedder	Embeds TrueType fonts into PDF documents for custom text rendering.
FontInfo	Information about a font used in a PDF.
FontRepository	Provides access to fonts available for use in PDF documents.
FontSource	Base class for font sources.
FontSourceCollection	A collection of font sources used by FontRepository.
FontSubstitution	Base type for font substitutions held in FontSubstitutionCollection.
FontSubstitutionCollection	Class with 9 methods and 3 properties.
FontUtilities	Provides font management utilities for a document.
MarkupParagraph	A paragraph within a markup section.
MarkupSection	A section of text on a page — a spatially coherent group of lines.
MemoryFontSource	A font source backed by an in-memory font byte buffer.
OneBasedList	Read-only list with 1-based indexer, matching the public API.
OriginalFontSpecification	Class with 1 method and 3 properties.
PageMarkup	Represents the text markup of a single page, organized into sections.
ParagraphAbsorber	Absorbs text from PDF pages and organizes it into sections and paragraphs.
ParagraphAbsorberOptions	Options for ParagraphAbsorber controlling section detection thresholds.
PdfFontView	Thin engine-font view used by Aspose.Pdf parity (Font.iPdfFont).
PhysicalTextSegment	Physical (page-space) projection of an absorbed TextSegment.
Position	The Position class can be used to specify X and Y indents for layout adjustments; its XIndent and YIndent properties are read‑only after construction.
RegexManager	Global configuration for regular-expression text search (for example via TextFragmentAbsorber).
SimpleFontSubstitution	Class with 3 methods and 3 properties.
SystemFontSource	A font source that searches the system's installed fonts.
TabStop	Represents a single tab stop position.
TabStops	A collection of tab stop positions for text layout.
TableAbsorber	Detects and extracts tables from PDF pages by analyzing text positions and line drawing operations.
TextAbsorber	Extracts text from PDF pages by parsing content streams.
TextBuilder	Appends text fragments to a PDF page by registering fonts in the page resources and writing content stream operators.
TextEditOptions	Options that control how text is edited (replaced, font-substituted, language-transformed).
TextExtractionError	Diagnostic produced by TextFragmentAbsorber when a page-level extraction fails or partially succeeds.
TextExtractionErrorLocation	Structured location of a TextExtractionError within a page's content stream.
TextExtractionOptions	Options for text extraction operations.
TextFormattingOptions	Represents text formatting options for a TextParagraph.
TextFragment	Represents a fragment of text on a page with position and style information.
TextFragmentAbsorber	Searches for text fragments on PDF pages, optionally matching a search phrase.
TextFragmentCollection	A 1-indexed collection of TextFragment objects, matching the public API.
TextFragmentState	Fragment-level text formatting state.
TextOptions	Base class for text-processing options.
TextParagraph	Represents a text paragraph that can be placed on a page via AppendParagraph.
TextReplaceOptions	Options for text replacement operations.
TextReplacer	Finds and replaces text in PDF content streams.
TextSearchOptions	Options for text search operations in PDF documents.
TextSegment	A single segment within a TextFragment.
TextSegmentCollection	A 1-indexed collection of TextSegment objects belonging to a TextFragment.
TextState	Text formatting state.

Interfaces

Interface	Description
IFontOptions	Per-font runtime options (currently only the font-embedding error toggle).

Enumerations

Enumeration	Description
ClippingPathsProcessingMode	How clipping paths are processed when text edits affect clipped regions.
CoordinateOrigin	How the lowest Y coordinate of a text fragment is interpreted in positioning APIs (CoordinateOrigin and per-segment SetPosition overloads).
FontReplace	Font-replacement strategy when the original font cannot encode replacement text.
FontSizeAdjustment	Font size adjustment strategy when replaced text has a different size.
FontStyles	Represents a position on a page.
FontSubsetStrategy	Strategy for font subsetting when saving a document.
FontType	Font type classification.
FontTypes	Stream-loadable font formats accepted by Stream, FontTypes).
LanguageTransformation	Language transformation behavior (RTL, ligatures, etc).
LineSpacingMode	How line spacing is interpreted (font-derived vs full glyph extent).
NoCharacterAction-Text	Action to perform if font does not contain required character.
ReplaceAdjustment	Specifies how text replacement adjustments are handled.
Scope-Text	Replace-scope selector (canonical screaming-snake naming).
TabAlignmentType	Tab alignment type for tab stops.
TabLeaderType	Tab leader character type.
TextFormattingMode	Specifies how extracted text is formatted.
TextRenderingMode	PDF text rendering mode (Tr operator).
WordWrapMode-Text	Word wrap mode that controls how text wraps within a paragraph rectangle.

Vector

Class	Description
GraphicElement	Single vector-graphics element (path segment, image, text run) extracted from a PDF content stream.
GraphicElementCollection	Mutable collection of GraphicElement entries.
GraphicsAbsorber	Extracts the painted vector sub-paths of a page as SubPath elements, each carrying its page-space bounding Rectangle.
SubPath	A single painted sub-path extracted from a content stream: its construction operators (in their original user-space coordinates), the CTM in effect when it was drawn, and the painting operator that closed it.
XFormPlacement	Class in the PDF .NET API.

Xmp

Class	Description
Metadata	XMP metadata accessor exposed by per-resource members such as Metadata.
XmpField	One named XMP field — a (prefix, local-name) pair plus a typed value.
XmpMetadata	Provides access to XMP metadata embedded in the PDF.
XmpPacketContainer	The XMP packet exposed by getData; its WorkingPacket yields the live RDF/XML.
XmpPdfAExtensionField	One field of a PDF/A XMP-extension structured value type.
XmpPdfAExtensionObject	One PDF/A XMP-extension property/value pair.
XmpPdfAExtensionProperty	One PDF/A XMP-extension property declaration (name, value, value type, category, description).
XmpPdfAExtensionSchema	One PDF/A XMP-extension schema, holding a description and its associated XmpPdfAExtensionObjects.
XmpPdfAExtensionSchemaDescription	Human-readable description of a PDF/A XMP extension schema.
XmpPdfAExtensionValueType	One PDF/A XMP-extension structured value type, holding its fields.
XmpValue	Represents a typed XMP metadata value.
XmpWorkingPacket	A working XMP packet; GetXml returns the packet's RDF/XML with rdf:RDF as the document element so callers can XPath into it.

Enumerations

Enumeration	Description
XmpFieldType	XMP field categories (matches the Aspose.Pdf reflection signature exactly — the underlying integer values are not load-bearing because callers compare against the named members).
XmpPdfAExtensionCategoryType	Whether a PDF/A XMP-extension property is for external (publicly visible) or internal (private) use.

---

Detailed Member Reference

Document and Pages

• Document
  • Create() -> Document
  • Open(path) -> Document / Open(data) -> Document / Open(stream) -> Document
  • Pages -> PageCollection
  • Form -> Form
  • Save(path) / Save(stream, options) / ToArray() -> byte[]
  • Encrypt(userPassword, ownerPassword, permissions, algorithm)
  • Decrypt()
• PageCollection
  • Add() -> Page / Add(width, height) -> Page
  • At(oneBasedIndex) -> Page
• Page
  • Annotations -> AnnotationCollection
  • Resources -> PageResources

Text

• TextAbsorber
  • Visit(page) / Visit(form) / Visit(pdf)
  • Text -> string
• TextFragmentAbsorber
  • Visit(page)
  • TextFragments -> TextFragmentCollection

Forms

• Field
  • ExportToJson(stream)
  • Flatten()
• ChoiceField
  • Options -> OptionCollection
  • AddOption(optionName) / AddOption(export, name)
  • DeleteOption(optionName)

Annotations and Actions

• AnnotationCollection
  • AddLinkAnnotation(rect, action)
  • AddStampAnnotation(rect, contents, stampName)
  • AddTextAnnotation(rect, contents, title, open)
  • AddFreeTextAnnotation(rect, contents, fontName, fontSize, color)
• PdfAction
  • CreateUri(uri)
  • CreateGoTo(pageIndex, fitType)
  • CreateJavaScript(script)
  • CreateNamed(name)
  • CreateLaunch(filePath)

Rendering

• SvgDevice
  • Process(page) -> string
  • Process(page, output) / Process(page, outputFileName)
• PngDevice / JpegDevice / BmpDevice / TiffDevice
  • Process(page, output) (inherited from ImageDevice)

</details>

Documentation & Resources

• Getting started guide — installation, walkthroughs, and feature guides for this library.
• How-to guides & FAQ — task-focused answers for common PDF-processing questions.
• Full API reference — the complete, browsable reference for all 854 public types (the API Reference section above covers the essentials).
• Found a bug or have a feature request? Open an issue on GitHub.

<details> <summary>View In-Repo Documentation Guides</summary>

Guide	Description
Getting Started	Installation, first program, core concepts (document lifecycle, 1-based page indexing, saving)
Working with Text	Extract, search, and replace text; build new text with TextBuilder / TextParagraph; tab stops
Working with Pages	Add, delete, reorder, rotate, and resize pages; copy pages across documents; merge & split
Fonts	Standard 14, embedding & subsetting, custom fonts (FontRepository), substitution, inspection
Working with Forms	Read, fill, and build AcroForm fields (text, checkbox, radio, choice, button, signature)
Working with Annotations	Read, create, and modify PDF annotations; watermarks; flatten
Bookmarks & Navigation	Outlines/bookmarks, named destinations, and page labels
Security and Encryption	Encrypt / decrypt (RC4 / AES-128 / AES-256), document permissions, digital signatures (PKCS#7)
Metadata & XMP	Document Info dictionary (Title/Author/…) and the XMP metadata packet
Converters	PDF ↔ HTML, PDF ↔ Markdown, PDF ↔ SVG, PDF → plain text
Rendering	Render pages to PNG, JPEG, BMP, TIFF; SVG output; resolution + color depth control
Optimization	Compress images, subset fonts, link duplicate streams, PDF/A validation + conversion
Working with Tables	Extract tabular data with TableAbsorber; build tables with Table / Row / Cell
Tagged PDF	Read and build /StructTreeRoot trees; ITaggedContent authoring API
Comparison	Side-by-side text comparison into a result PDF, graphical page diff, and the Diff edit model
Facades	High-level task-oriented APIs (PdfFileEditor, PdfFileSecurity, PdfFileSignature, PdfBookmarkEditor, PdfContentEditor, ...)
API Reference	Public classes organised by namespace, plus a "not included vs Aspose.PDF for .NET" list

</details>

Scope and Limitations

• AI / LowCode workflows (Aspose.Pdf.AI.*, Aspose.Pdf.LowCode.*) are out of scope by design — use Aspose.PDF for .NET for OpenAI / Llama-powered summarisation, OCR-aided extraction, and the LowCode façade APIs.
• Multithreading APIs (Aspose.Pdf.Multithreading.*) are not included; this edition is single-threaded for a single Document instance.
• Format converters are limited to PDF, HTML, SVG, Markdown, and XML — DOCX, EPUB, MHT, XPS, PCL, LaTeX, DJVU, OFD, PostScript, and CGM conversion are not included.
• PdfViewer's Print* methods throw PlatformNotSupportedException; render to an image and pass it to your own printing stack instead.
• Basic digital signatures (sign / verify, PKCS#1, PKCS#7, DocMDP, certifying) work, but the validation-options surface — ValidationOptions, ValidationResult, OCSP, network timestamping, custom remote-sign delegates — is stored but not active.
• Advanced PdfFileEditor features (MakeNUp imposition, MakeBooklet from a Stream with non-trivial margins, ResizeContents with custom imposition matrices) are accepted as input, but the save path emits a simplified layout.
• Dynamic XFA forms are read, laid out from their own content — field heights, per-edge border chrome, captions, rich text — and can be flattened to real AcroForm pages; XFA datasets round-trip through the AcroForm /XFA entry, sync with AcroForm fields, and export / import via FDF, XFDF, and XML. Fine-grained authoring of individual XFA dataset fields is still limited.
• PDF3DAnnotation content (artwork, views, cross-sections, lighting) is read and round-trips, but the 3D content stream is not regenerated on save and the page renderer does not display the 3D model.
• Side-by-side comparison is text-based: it compares extracted text runs, so a change that leaves the text identical — a recoloured heading, a moved image — does not register. Use GraphicalPdfComparer for those, bearing in mind it is Windows only.
• The structure tree is built and round-trips through /StructTreeRoot, but advanced PDF/UA-2 layout-aware tagging features are partial.
• PDF/A level validation works, but certain PDF/A-2 / PDF/A-3 conversion fix-ups (transparency flattening, embedded-file constraints, ICC profile downgrade) are stored but not applied.
• Complex colour spaces (DeviceN / Separation with more than 4 channels, ICC-based CMYK group blending) render in approximate sRGB.
• Rendering output is pixel-close but not byte-identical to Aspose.PDF for .NET — sub-pixel glyph positioning, image dithering, anti-aliasing weight, and widget-appearance details may differ slightly.
• TiffDevice.BinarizeBradley and DocumentCollection.GetEnumerator() are not yet implemented and throw NotImplementedException.

These limitations don't apply to Aspose.PDF for .NET — Enterprise Edition, which adds broader format support and full feature coverage — AI / LowCode workflows, complete XFA authoring, advanced digital-signature validation, multithreading, and conversion to many additional formats (DOCX, EPUB, XPS, PCL, PostScript, and more).

Development and Testing

dotnet test tests/Aspose.Pdf.Foss.Tests.csproj

The test project (Aspose.Pdf.Foss.Tests) is an xUnit suite; every runnable example in this README traces back to a real test method in tests/ — including tests/AnnotationCreationTests.cs, tests/Actions/PdfActionTests.cs, tests/ChoiceFieldOptionsTests.cs, and tests/Content/ContentExtractionTests.cs. CI runs the same restore/build/test sequence on Windows via .github/workflows/build.yml.

License

This project is licensed under the MIT License. The MIT License permits use, copying, modification, distribution, sublicensing, and commercial use, provided its copyright and permission notice are retained. The software is provided without warranty.