ZipCrc Delphi DLL Reference Documentation


Current Version:

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


myObject: HCkZipCrc;

myObject := CkZipCrc_Create();

// ...

function CkZipCrc_Create: HCkZipCrc; stdcall;

Creates an instance of the HCkZipCrc object and returns a handle (i.e. a Pointer). The handle is passed in the 1st argument for the functions listed on this page.

procedure CkZipCrc_Dispose(handle: HCkZipCrc); stdcall;

Objects created by calling CkZipCrc_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function.


function CkZipCrc_getLastMethodSuccess(objHandle: HCkZipCrc): wordbool; stdcall;
procedure CkZipCrc_putLastMethodSuccess(objHandle: HCkZipCrc; newPropVal: wordbool); stdcall;

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.



procedure CkZipCrc_BeginStream(objHandle: HCkZipCrc) stdcall;

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.

function CkZipCrc_CalculateCrc(objHandle: HCkZipCrc;
    data: HCkByteData): LongWord; stdcall;

Calculates a 32-bit CRC for in-memory byte data. This is the 32-bit CRC that would be found in a Zip file header if a file containing the data was added to a zip archive. Returns the CRC32 of the data.

function CkZipCrc_EndStream(objHandle: HCkZipCrc): LongWord; stdcall;

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

function CkZipCrc_FileCrc(objHandle: HCkZipCrc;
    path: PWideChar): LongWord; stdcall;

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 (1)
function CkZipCrc_FileCrcAsync(objHandle: HCkZipCrc;
    path: PWideChar): HCkTask; stdcall;

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 nil on failure

procedure CkZipCrc_MoreData(objHandle: HCkZipCrc;
    data: HCkByteData) stdcall;

Adds additional data to the CRC currently being calculated. (See BeginStream for more information.)

function CkZipCrc_ToHex(objHandle: HCkZipCrc;
    crc: Integer;
    outStr: HCkString): wordbool; stdcall;
function CkZipCrc__toHex(objHandle: HCkZipCrc;
    crc: Integer): PWideChar; stdcall;

Converts a 32-bit integer to a hex string.

Returns True for success, False for failure.