Class RandomAccessStreamDataProvider

An implementation of IDataProvider that wraps a Windows.Storage.Streams.IRandomAccessStream.

Inheritance

System.Object

RandomAccessStreamDataProvider

Implements

IDataProvider

Namespace: PSPDFKitFoundation.Data

Assembly: PSPDFKitFoundation.dll

Syntax

public sealed class RandomAccessStreamDataProvider : IDataProvider

Constructors

RandomAccessStreamDataProvider(IRandomAccessStream)

Constructs a RandomAccessStreamDataProvider from an Windows.Storage.Streams.IRandomAccessStream.

Declaration

public RandomAccessStreamDataProvider(IRandomAccessStream stream)

Parameters

Type	Name	Description
Windows.Storage.Streams.IRandomAccessStream	stream	The Windows.Storage.Streams.IRandomAccessStream that provides the data.

RandomAccessStreamDataProvider(IRandomAccessStream, String)

Constructs a RandomAccessStreamDataProvider from an Windows.Storage.Streams.IRandomAccessStream.
A stable hash code will be created from the string passed in, helpful for persisting the same document id through application restarts and document changes.

Declaration

public RandomAccessStreamDataProvider(IRandomAccessStream stream, string hashString)

Parameters

Type	Name	Description
Windows.Storage.Streams.IRandomAccessStream	stream	The Windows.Storage.Streams.IRandomAccessStream that provides the data.
System.String	hashString	A string (usually an id or file name) used to identify the document persistently.

Properties

Size

Returns the size of the data.

Declaration

public ulong Size { get; }

Property Value

Type	Description
System.UInt64

SupportsWriting

Specifies whether a write can be attempted using ReplaceWithDataSinkAsync(IDataSink).

Declaration

public bool SupportsWriting { get; }

Property Value

Type	Description
System.Boolean

Uid

Returns a Uid that enables you to uniquely identify this data provider.
The Uid for the same provider might change between application restarts.
For persisting it, you must either implement your own mechanism, or use the RandomAccessStreamDataProvider(IRandomAccessStream, String) constructor to pin the hashCode to a persistent id representing the document.

Declaration

public string Uid { get; set; }

Property Value

Type	Description
System.String

Methods

CreateDataSink(DataSinkOption)

This method creates a data sink for your data provider with the given DataSinkOption. PSPDFKit will write all the appropriate data into it and pass it to ReplaceWithDataSinkAsync(IDataSink) when appropriate.

Declaration

public IDataSink CreateDataSink(DataSinkOption option)

Parameters

Type	Name	Description
DataSinkOption	option	The desired options for the DataSink.

Returns

Type	Description
IDataSink

ReadAsync(UInt32, UInt32)

Reads and returns data read from offset with size. You have to make sure not to read past the end of your data.

Declaration

public IAsyncOperation<IBuffer> ReadAsync(uint size, uint offset)

Parameters

Type	Name	Description
System.UInt32	size	The requested amount of data to read.
System.UInt32	offset	The offset into the data source to start reading from.

Returns

Type	Description
Windows.Foundation.IAsyncOperation<Windows.Storage.Streams.IBuffer>

ReplaceWithDataSinkAsync(IDataSink)

This method should replace your current data with the one written into the data sink. To create a data sink, see CreateDataSink(DataSinkOption).
Depending on the DataSinkOption used you either have to append or replace the data.

Declaration

public IAsyncOperation<bool> ReplaceWithDataSinkAsync(IDataSink dataSink)

Parameters

Type	Name	Description
IDataSink	dataSink	The object instantiated with CreateDataSink(DataSinkOption).

Returns

Type	Description
Windows.Foundation.IAsyncOperation<System.Boolean>

Implements

IDataProvider