Compression VB.NET Reference Documentation

Compression

Data compression component implementing the PPMD, Bzip2, Deflate, and LZW compression algorithms. .NET, ActiveX, and C++ implementations provide progress monitoring and abort capabilities. Provides a unified API for all supported compression algorithms.

Object Creation

Dim obj As New Chilkat.Compression()

Properties

Algorithm As String

The compression algorithm to be used. Should be set to either "ppmd", "deflate", "zlib", "bzip2", or "lzw".

Note: The PPMD compression algorithm is only available for 32-bit builds. It is not available for 64-bit implementations. Also, this PPMD implementation is the "J" variant.

Charset As String

Only applies to methods that compress or decompress strings. This specifies the character encoding that the string should be converted to before compression. Many programming languages use Unicode (2 bytes per char) for representing characters. This property allows for the string to be converted to a 1-byte per char encoding prior to compression.

DebugLogFilePath As String

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

EncodingMode As String

Controls the encoding expected by methods ending in "ENC", such as CompressBytesENC. Valid values are "base64", "hex", "url", and "quoted-printable". Compression methods ending in ENC return the binary compressed data as an encoded string using this encoding. Decompress methods expect the input string to be this encoding.

HeartbeatMs As Integer

The number of milliseconds between each AbortCheck event callback. The AbortCheck callback allows an application to abort any method call prior to completion. If HeartbeatMs is 0 (the default), no AbortCheck event callbacks will fire.

LastErrorHtml As String (ReadOnly)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

LastErrorText As String (ReadOnly)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

Concept of LastErrorText

LastErrorText Standard Information

LastErrorXml As String (ReadOnly)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

LastMethodSuccess As Boolean

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = True and failure = False.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

VerboseLogging As Boolean

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version As String (ReadOnly)

Version of the component/library, such as "9.5.0.63"

Methods

Function BeginCompressBytes(ByVal data As Byte()) As Byte()

Large amounts of binary byte data may be compressed in chunks by first calling BeginCompressBytes, followed by 0 or more calls to MoreCompressedBytes, and ending with a final call to EndCompressBytes. Each call returns 0 or more bytes of compressed data which may be output to a compressed data stream (such as a file, socket, etc.).

Returns an empty byte array on failure

Compress Large Binary File in Blocks

Function BeginCompressBytesAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the BeginCompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function BeginCompressBytesENC(ByVal data As Byte()) As String

Large amounts of binary byte data may be compressed in chunks by first calling BeginCompressBytesENC, followed by 0 or more calls to MoreCompressedBytesENC, and ending with a final call to EndCompressBytesENC. Each call returns 0 or more characters of compressed data (encoded as a string according to the EncodingMode property setting) which may be output to a compressed data stream (such as a file, socket, etc.).

Returns Nothing on failure

Function BeginCompressBytesENCAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the BeginCompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function BeginCompressString(ByVal str As String) As Byte()

Large amounts of string data may be compressed in chunks by first calling BeginCompressString, followed by 0 or more calls to MoreCompressedString, and ending with a final call to EndCompressString. Each call returns 0 or more bytes of compressed data which may be output to a compressed data stream (such as a file, socket, etc.).

Returns an empty byte array on failure

Compress Text Feed to Binary

Function BeginCompressStringAsync(ByVal str As String) As Task

Creates an asynchronous task to call the BeginCompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function BeginCompressStringENC(ByVal str As String) As String

Large amounts of string data may be compressed in chunks by first calling BeginCompressStringENC, followed by 0 or more calls to MoreCompressedStringENC, and ending with a final call to EndCompressStringENC. Each call returns 0 or more characters of compressed data (encoded as a string according to the EncodingMode property setting) which may be output to a compressed data stream (such as a file, socket, etc.).

Returns Nothing on failure

Compress String Feed to Base64

Function BeginCompressStringENCAsync(ByVal str As String) As Task

Creates an asynchronous task to call the BeginCompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function BeginDecompressBytes(ByVal data As Byte()) As Byte()

A compressed data stream may be decompressed in chunks by first calling BeginDecompressBytes, followed by 0 or more calls to MoreDecompressedBytes, and ending with a final call to EndDecompressBytes. Each call returns 0 or more bytes of decompressed data.

Returns an empty byte array on failure

Decompress Large Binary File in Blocks

Function BeginDecompressBytesAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the BeginDecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function BeginDecompressBytesENC(ByVal str As String) As Byte()

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressBytesENC, followed by 0 or more calls to MoreDecompressedBytesENC, and ending with a final call to EndDecompressBytesENC. Each call returns 0 or more bytes of decompressed data.

Returns an empty byte array on failure

Function BeginDecompressBytesENCAsync(ByVal str As String) As Task

Creates an asynchronous task to call the BeginDecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function BeginDecompressString(ByVal data As Byte()) As String

A compressed data stream may be decompressed in chunks by first calling BeginDecompressString, followed by 0 or more calls to MoreDecompressedString, and ending with a final call to EndDecompressString. Each call returns 0 or more characters of decompressed text.

Returns Nothing on failure

Decompress Large Text File in Blocks

Function BeginDecompressStringAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the BeginDecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function BeginDecompressStringENC(ByVal str As String) As String

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressStringENC, followed by 0 or more calls to MoreDecompressedStringENC, and ending with a final call to EndDecompressStringENC. Each call returns 0 or more characters of decompressed text.

Returns Nothing on failure

Function BeginDecompressStringENCAsync(ByVal str As String) As Task

Creates an asynchronous task to call the BeginDecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function CompressBd(ByVal binData As BinData) As Boolean

Introduced in version 9.5.0.66

Compresses the data contained in a BinData object.

Returns True for success, False for failure.

Compress and Decompress Base64

Compress and Decompress Hex String

Function CompressBdAsync(ByVal binData As BinData) As Task

Introduced in version 9.5.0.66

Creates an asynchronous task to call the CompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function CompressBytes(ByVal data As Byte()) As Byte()

Compresses byte data.

Returns an empty byte array on failure

Compress Bytes

Function CompressBytesAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the CompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function CompressBytesENC(ByVal data As Byte()) As String

Compresses bytes and returns the compressed data encoded to a string. The encoding (hex, base64, etc.) is determined by the EncodingMode property setting.

Returns Nothing on failure

Compress Bytes to Base64 (or any other encoding)

Function CompressBytesENCAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the CompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function CompressFile(ByVal srcPath As String, ByVal destPath As String) As Boolean

Performs file-to-file compression. Files of any size may be compressed because the file is compressed internally in streaming mode.

Returns True for success, False for failure.

Compress and Decompress a File

Function CompressFileAsync(ByVal srcPath As String, ByVal destPath As String) As Task

Creates an asynchronous task to call the CompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function CompressStream(ByVal strm As Stream) As Boolean

Introduced in version 9.5.0.56

Compresses a stream. Internally, the strm's source is read, compressed, and the compressed data written to the strm's sink. It does this in streaming fashion. Extremely large or even infinite streams can be compressed with stable ungrowing memory usage.

Returns True for success, False for failure.

Streaming Compression

Function CompressStreamAsync(ByVal strm As Stream) As Task

Introduced in version 9.5.0.56

Creates an asynchronous task to call the CompressStream method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function CompressString(ByVal str As String) As Byte()

Compresses a string.

Returns an empty byte array on failure

Compress and Decompress a String

Function CompressStringAsync(ByVal str As String) As Task

Creates an asynchronous task to call the CompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function CompressStringENC(ByVal str As String) As String

Compresses a string and returns the compressed data encoded to a string. The output encoding (hex, base64, etc.) is determined by the EncodingMode property setting.

Returns Nothing on failure

Compress and Decompress a String

Function CompressStringENCAsync(ByVal str As String) As Task

Creates an asynchronous task to call the CompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function DecompressBd(ByVal binData As BinData) As Boolean

Introduced in version 9.5.0.66

Decompresses the data contained in a BinData object.

Returns True for success, False for failure.

Compress and Decompress Base64

Compress and Decompress Hex String

Function DecompressBdAsync(ByVal binData As BinData) As Task

Introduced in version 9.5.0.66

Creates an asynchronous task to call the DecompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function DecompressBytes(ByVal data As Byte()) As Byte()

The opposite of CompressBytes.

Returns an empty byte array on failure

Decompress Bytes

Function DecompressBytesAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the DecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function DecompressBytesENC(ByVal encodedCompressedData As String) As Byte()

The opposite of CompressBytesENC. encodedCompressedData contains the compressed data as an encoded string (hex, base64, etc) as specified by the EncodingMode property setting.

Returns an empty byte array on failure

Compress Bytes to Base64 (or any other encoding)

Function DecompressBytesENCAsync(ByVal encodedCompressedData As String) As Task

Creates an asynchronous task to call the DecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function DecompressFile(ByVal srcPath As String, ByVal destPath As String) As Boolean

Performs file-to-file decompression (the opposite of CompressFile). Internally the file is decompressed in streaming mode which allows files of any size to be decompressed.

Returns True for success, False for failure.

Compress and Decompress a File

Function DecompressFileAsync(ByVal srcPath As String, ByVal destPath As String) As Task

Creates an asynchronous task to call the DecompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function DecompressStream(ByVal strm As Stream) As Boolean

Introduced in version 9.5.0.56

Decompresses a stream. Internally, the strm's source is read, decompressed, and the decompressed data written to the strm's sink. It does this in streaming fashion. Extremely large or even infinite streams can be decompressed with stable ungrowing memory usage.

Returns True for success, False for failure.

Streaming Compression

Function DecompressStreamAsync(ByVal strm As Stream) As Task

Introduced in version 9.5.0.56

Creates an asynchronous task to call the DecompressStream method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function DecompressString(ByVal data As Byte()) As String

Takes compressed bytes, decompresses, and returns the resulting string.

Returns Nothing on failure

Compress and Decompress a String

Function DecompressStringAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the DecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function DecompressStringENC(ByVal encodedCompressedData As String) As String

The opposite of CompressStringENC. encodedCompressedData contains the compressed data as an encoded string (hex, base64, etc) as specified by the EncodingMode property setting.

Returns Nothing on failure

Compress and Decompress a String

Function DecompressStringENCAsync(ByVal encodedCompressedData As String) As Task

Creates an asynchronous task to call the DecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndCompressBytes() As Byte()

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressBytes)

Returns an empty byte array on failure

Compress Large Binary File in Blocks

Function EndCompressBytesAsync() As Task

Creates an asynchronous task to call the EndCompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndCompressBytesENC() As String

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressBytesENC)

Returns Nothing on failure

Function EndCompressBytesENCAsync() As Task

Creates an asynchronous task to call the EndCompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndCompressString() As Byte()

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressString)

Returns an empty byte array on failure

Compress Text Feed to Binary

Function EndCompressStringAsync() As Task

Creates an asynchronous task to call the EndCompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndCompressStringENC() As String

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressStringENC)

Returns Nothing on failure

Compress String Feed to Base64

Function EndCompressStringENCAsync() As Task

Creates an asynchronous task to call the EndCompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndDecompressBytes() As Byte()

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

(See BeginDecompressBytes)

Returns an empty byte array on failure

Decompress Large Binary File in Blocks

Function EndDecompressBytesAsync() As Task

Creates an asynchronous task to call the EndDecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndDecompressBytesENC() As Byte()

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressBytesENC)

Returns an empty byte array on failure

Function EndDecompressBytesENCAsync() As Task

Creates an asynchronous task to call the EndDecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndDecompressString() As String

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

(See BeginDecompressString)

Returns Nothing on failure

Decompress Large Text File in Blocks

Function EndDecompressStringAsync() As Task

Creates an asynchronous task to call the EndDecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function EndDecompressStringENC() As String

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressStringENC)

Returns Nothing on failure

Function EndDecompressStringENCAsync() As Task

Creates an asynchronous task to call the EndDecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreCompressBytes(ByVal data As Byte()) As Byte()

(See BeginCompressBytes)

Returns an empty byte array on failure

Compress Large Binary File in Blocks

Function MoreCompressBytesAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the MoreCompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreCompressBytesENC(ByVal data As Byte()) As String

(See BeginCompressBytesENC)

Returns Nothing on failure

Function MoreCompressBytesENCAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the MoreCompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreCompressString(ByVal str As String) As Byte()

(See BeginCompressString)

Returns an empty byte array on failure

Compress Text Feed to Binary

Function MoreCompressStringAsync(ByVal str As String) As Task

Creates an asynchronous task to call the MoreCompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreCompressStringENC(ByVal str As String) As String

(See BeginCompressStringENC)

Returns Nothing on failure

Compress String Feed to Base64

Function MoreCompressStringENCAsync(ByVal str As String) As Task

Creates an asynchronous task to call the MoreCompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreDecompressBytes(ByVal data As Byte()) As Byte()

(See BeginDecompressBytes)

Returns an empty byte array on failure

Decompress Large Binary File in Blocks

Function MoreDecompressBytesAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the MoreDecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreDecompressBytesENC(ByVal str As String) As Byte()

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressBytesENC)

Returns an empty byte array on failure

Function MoreDecompressBytesENCAsync(ByVal str As String) As Task

Creates an asynchronous task to call the MoreDecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreDecompressString(ByVal data As Byte()) As String

(See BeginDecompressString)

Returns Nothing on failure

Decompress Large Text File in Blocks

Function MoreDecompressStringAsync(ByVal data As Byte()) As Task

Creates an asynchronous task to call the MoreDecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function MoreDecompressStringENC(ByVal str As String) As String

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressStringENC)

Returns Nothing on failure

Function MoreDecompressStringENCAsync(ByVal str As String) As Task

Creates an asynchronous task to call the MoreDecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nothing on failure

How to Run an Asynchronous Task

Function SaveLastError(ByVal path As String) As Boolean

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns True for success, False for failure.

Function UnlockComponent(ByVal unlockCode As String) As Boolean

Unlocks the component allowing for the full functionality to be used. The component may be used fully-functional for the 1st 30-days after download by passing an arbitrary string to this method. If for some reason you do not receive the full 30-day trial, send email to support@chilkatsoft.com for a temporary unlock code w/ an explicit expiration date. Upon purchase, a purchased unlock code is provided which should replace the temporary/arbitrary string passed to this method.

Returns True for success, False for failure.

Diagnosing UnlockComponent Problems

UnlockComponent LastErrorText shows exact string passed to it.

Verify UnlockComponent Success w/ Permanent Unlock Code

LastErrorText Standard Information

Events

Event OnAbortCheck

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200.

Args are passed using Chilkat.AbortCheckEventArgs

Event callback implementation:

Dim WithEvents compression As Chilkat.Compression

Private Sub compression_OnAbortCheck(sender As Object, args As Chilkat.AbortCheckEventArgs) Handles compression.OnAbortCheck

    ...

End Sub

Event OnBinaryData

Binary data provided by certain methods.

Args are passed using Chilkat.BinaryDataEventArgs

Event callback implementation:

Dim WithEvents compression As Chilkat.Compression

Private Sub compression_OnBinaryData(sender As Object, args As Chilkat.BinaryDataEventArgs) Handles compression.OnBinaryData

    ...

End Sub

Event OnPercentDone

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

The abort output argument provides a means for aborting the operation. Setting it to True will cause the method to abort and return a failed status (or whatever return value indicates failure).

Args are passed using Chilkat.PercentDoneEventArgs

Event callback implementation:

Dim WithEvents compression As Chilkat.Compression

Private Sub compression_OnPercentDone(sender As Object, args As Chilkat.PercentDoneEventArgs) Handles compression.OnPercentDone

    ...

End Sub

Event OnProgressInfo

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

Args are passed using Chilkat.ProgressInfoEventArgs

Event callback implementation:

Dim WithEvents compression As Chilkat.Compression

Private Sub compression_OnProgressInfo(sender As Object, args As Chilkat.ProgressInfoEventArgs) Handles compression.OnProgressInfo

    ...

End Sub

Event OnTaskCompleted

Called in the background thread when an asynchronous task completes.

VB.NET TaskCompleted Event Callback Example

Args are passed using Chilkat.TaskCompletedEventArgs

Event callback implementation:

Dim WithEvents compression As Chilkat.Compression

Private Sub compression_OnTaskCompleted(sender As Object, args As Chilkat.TaskCompletedEventArgs) Handles compression.OnTaskCompleted

    ...

End Sub

Event OnTextData

Text data provided by certain methods.

Args are passed using Chilkat.TextDataEventArgs

Event callback implementation:

Dim WithEvents compression As Chilkat.Compression

Private Sub compression_OnTextData(sender As Object, args As Chilkat.TextDataEventArgs) Handles compression.OnTextData

    ...

End Sub