ZipCrc Lianja Reference Documentation

ZipCrc

Calculate a Zip CRC checksum for a file or in-memory data.

Object Creation

loObject = createobject("CkZipCrc")

Properties

LastMethodSuccess As Boolean

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of .T. indicates success, a value of .F. 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 = .T. and failure = .F..
  • 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 .T.. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

Methods

BeginStream()

Provides a way to calculate a CRC by streaming the data a chunk at a time. An application would start by calling BeginStream. Then it would add data by calling MoreData for each additional chunk. After the last chunk has been processed, the EndStream method is called to return the CRC.

EndStream() As Numeric

Finalizes and returns the Zip CRC value calculated by calling BeginStream followed by multiple calls to MoreData.

FileCrc(path As Character) As Numeric

Calculates the CRC32 of a file. The data contained in the file is streamed for the calculation to keep the memory footprint small and constant. Returns the CRC32 of the file.

FileCrcAsync(path As Character) As CkTask

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

Returns .F. on failure

How to Run an Asynchronous Task

ToHex(crc As Numeric) As Character

Converts a 32-bit integer to a hex string.

Returns .F. on failure