PdfObject Class

Namespace:: GemBox.Pdf

Assembly:: GemBox.Pdf.dll

Represents a base class for all types that implement various PDF components in the GemBox.Pdf assembly.

C#
VB.NET

public abstract class PdfObject

Public MustInherit Class PdfObject

Inheritance:: Object
PdfObject

Remarks

GemBox.Pdf assembly doesn't publicly expose constructors for types assignable from PdfObject (except PdfDocument), PdfContentElement, and PdfBasicObject types. These types are instead instantiated either through static Create or other factory methods.

Reasons for this is to support either the current or future extensibility of the type without affecting backward compatibility and without using composition to reduce the number of object allocations.

For example, PdfNumber type is implemented as PdfInteger and internal PdfReal type. When using Create(Double) method, GemBox.Pdf assembly is able to create either PdfReal or PdfInteger, or return a cached instance of PdfInteger available for an implementation-defined interval of integers, thus reducing memory overhead.

PdfString and PdfName types have several internal implementations that reduce the number of Array allocations.

PdfArray type is currently implemented as a dynamic array. In the future, GemBox.Pdf assembly might provide an internal implementation that is immutable (without a need to use composition) to reduce memory overhead and optimize cloning operation.

PdfDictionary type is currently implemented as a hash table with a separate chaining collision resolution. In the future, GemBox.Pdf assembly might provide an internal implementation that uses dynamic array (without a need to use composition) if number of entries is small, to reduce memory overhead and, potentially, improve performance.

All these current and future implementations would not be possible in a backward compatible way (without unnecessary usage of composition) if constructors were publicly exposed.

Properties

Metadata

(Optional; PDF 1.4) A metadata stream containing metadata for the component.

C#
VB.NET

public virtual PdfXmlMetadataStream Metadata { get; }

Public Overridable ReadOnly Property Metadata As PdfXmlMetadataStream

Property Value

PdfXmlMetadataStream

A metadata stream containing metadata for the component.

Exceptions

InvalidPdfDictionaryEntryException

Value is not according to PDF Specification ISO 32000-1:2008.

Extension Methods

PdfObjectExtensions.GetDictionary(PdfObject)

PdfObjectExtensions.GetOrAddDictionary(PdfObject)

PdfObjectExtensions.GetArray(PdfObject)