ISCardCmd::get_ApduLength method

Article
01/07/2021

[The get_ApduLength method is available for use in the operating systems specified in the Requirements section. It is not available for use in Windows Server 2003 with Service Pack 1 (SP1) and later, Windows Vista, Windows Server 2008, and subsequent versions of the operating system. The Smart Card Modules provide similar functionality.]

The get_ApduLength method determines the length, in bytes, f the application protocol data unit (APDU).

Syntax

HRESULT get_ApduLength(
  [out] LONG *plSize
);

Parameters

plSize [out]: Pointer to the length of the APDU.

Return value

The method returns one of the following possible values.

Return code	Description
S_OK	Operation completed successfully.
E_INVALIDARG	The plSize parameter is not valid.
E_POINTER	A bad pointer was passed in plSize.
E_OUTOFMEMORY	Out of memory.

Remarks

To retrieve the raw application protocol data unit (APDU) from the byte buffer mapped through an IStream that contains the APDU message, call get_Apdu.

For a list of all the methods provided by this interface, see ISCardCmd.

In addition to the COM error codes listed above, this interface may return a smart card error code if a smart card function was called to complete the request. For more information, see Smart Card Return Values.

Examples

The following example shows how to retrieve the application protocol data unit (APDU) length. The example assumes that pISCardCmd is a valid pointer to an instance of the ISCardCmd interface.

LONG    lLen;
HRESULT hr;

// Retrieve the APDU length.
hr = pISCardCmd->get_ApduLength(&lLen);
if (FAILED(hr))
{
    printf("Failed get_ApduLength\n");
    // Take other error handling action.
}
else
    printf("Length returned is %d\n", lLen);

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
End of client support	Windows XP
End of server support	Windows Server 2003
Header	Scarddat.h
Type library	Scarddat.tlb
DLL	Scardssp.dll
IID	IID_ISCardCmd is defined as D5778AE3-43DE-11D0-9171-00AA00C18068