SCardDisconnect function (winscard.h)

Article
10/13/2021

The SCardDisconnect function terminates a connection previously opened between the calling application and a smart card in the target reader.

Syntax

LONG SCardDisconnect(
  [in] SCARDHANDLE hCard,
  [in] DWORD       dwDisposition
);

Parameters

[in] hCard

Reference value obtained from a previous call to SCardConnect.

[in] dwDisposition

Action to take on the card in the connected reader on close.

Value	Meaning
SCARD_LEAVE_CARD	Do not do anything special.
SCARD_RESET_CARD	Reset the card.
SCARD_UNPOWER_CARD	Power down the card.
SCARD_EJECT_CARD	Eject the card.

Return value

This function returns different values depending on whether it succeeds or fails.

Return code	Description
Success	SCARD_S_SUCCESS.
Failure	An error code. For more information, see Smart Card Return Values.

Remarks

If an application (which previously called SCardConnect) exits without calling SCardDisconnect, the card is automatically reset.

The SCardDisconnect function is a smart card and reader access function. For more information on other access functions, see Smart Card and Reader Access Functions.

Examples

The following example terminates the specified smart card connection. The example assumes that lReturn is a variable of type LONG, and that hCardHandle is a valid handle received from a previous call to SCardConnect.


lReturn = SCardDisconnect(hCardHandle, 
                          SCARD_LEAVE_CARD);
if ( SCARD_S_SUCCESS != lReturn )
{
    printf("Failed SCardDisconnect\n");
    exit(1);  // Or other appropriate action.
}

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	winscard.h
Library	Winscard.lib
DLL	Winscard.dll

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