Class PdfStreamAvailability

Namespace

nebulae.dotPDFium

Assembly

dotPDFium.dll

Provides an interface for managing the availability of PDF data streams, enabling incremental loading and access to PDF documents and their components.

public sealed class PdfStreamAvailability : IDisposable

Inheritance

object

PdfStreamAvailability

Implements

IDisposable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

This class is designed to facilitate the loading of PDF documents in scenarios where the data is retrieved incrementally, such as from a network stream. It provides methods to check the availability of the document, individual pages, and form data, as well as to determine whether the file is linearized (optimized for fast web viewing). Instances of this class must be disposed of when no longer needed to release unmanaged resources.

Constructors

PdfStreamAvailability(PdfStreamAvailabilityOptions)

Initializes a new instance of the PdfStreamAvailability class, which provides functionality for managing PDF stream availability using custom data access and availability callbacks.

public PdfStreamAvailability(PdfStreamAvailabilityOptions options)

Parameters

options PdfStreamAvailabilityOptions

A PdfStreamAvailabilityOptions object that specifies the configuration for the PDF stream availability, including user data, data access callbacks, and availability checks.

Remarks

This constructor initializes the PDF stream availability context by pinning the provided user data and delegates to prevent garbage collection during the lifetime of the instance. It also sets up the necessary native interop structures for managing PDF data availability and download hints.

Exceptions

ArgumentNullException

Thrown if options is null or if any of its required properties (UserData, GetBlock, IsDataAvailable, or RequestSegment) are null.

dotPDFiumException

Methods

Dispose()

Releases all resources used by the current instance of the class.

public void Dispose()

Remarks

This method should be called when the instance is no longer needed to free unmanaged resources and release any allocated handles. After calling this method, the instance should not be used.

IsDocAvailable()

Determines whether the document is available for processing.

public bool IsDocAvailable()

Returns

bool

true if the document is available; otherwise, false.

Remarks

This method checks the availability of the document using the underlying PDF data availability mechanism. It is typically used to verify whether the document can be accessed or processed further.

IsFormAvailable()

Determines whether the form data in the PDF document is available for use.

public bool IsFormAvailable()

Returns

bool

true if the form data is available; otherwise, false.

Remarks

This method checks the availability of form data in the PDF document. It may be useful in scenarios where form data needs to be processed or accessed.

IsLinearized()

Returns whether the underlying file is linearized (Fast Web View).

public bool IsLinearized()

Returns

bool

IsPageAvailable(int)

Determines whether the specified page is available for viewing or processing.

public bool IsPageAvailable(int pageIndex)

Parameters

pageIndex int

The zero-based index of the page to check.

Returns

bool

true if the specified page is available; otherwise, false.

Remarks

This method checks the availability of a page in the document, which may depend on factors such as the document's loading state or the availability of required resources.

TryLoadDocument(string)

Attempts to load the PDF document from this availability context.

public PdfDocument? TryLoadDocument(string password = "")

Parameters

password string

The password, or empty string for no password.

Returns

PdfDocument

A PdfDocument instance if the document is available; otherwise null.

Exceptions

dotPDFiumException

If PDFium returns an invalid handle despite IsDocAvailable returning true.