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SCARD_READERSTATEA structure (winscard.h)

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The SCARD_READERSTATE structure is used by functions for tracking smart cards within readers.

Syntax

typedef struct {
  LPCSTR szReader;
  LPVOID pvUserData;
  DWORD  dwCurrentState;
  DWORD  dwEventState;
  DWORD  cbAtr;
  BYTE   rgbAtr[36];
} SCARD_READERSTATEA, *PSCARD_READERSTATEA, *LPSCARD_READERSTATEA;

Members

szReader

A pointer to the name of the reader being monitored.

Set the value of this member to "\\?PnP?\Notification" and the values of all other members to zero to be notified of the arrival of a new smart card reader.

pvUserData

Not used by the smart card subsystem. This member is used by the application.

dwCurrentState

Current state of the reader, as seen by the application. This field can take on any of the following values, in combination, as a bitmask.

Value Meaning
SCARD_STATE_UNAWARE
 The application is unaware of the current state, and would like to know. The use of this value results in an immediate return from state transition monitoring services. This is represented by all bits set to zero.
SCARD_STATE_IGNORE
 The application is not interested in this reader, and it should not be considered during monitoring operations. If this bit value is set, all other bits are ignored.
SCARD_STATE_UNAVAILABLE
 The application expects that this reader is not available for use. If this bit is set, then all the following bits are ignored.
SCARD_STATE_EMPTY
 The application expects that there is no card in the reader. If this bit is set, all the following bits are ignored.
SCARD_STATE_PRESENT
 The application expects that there is a card in the reader.
SCARD_STATE_ATRMATCH
 The application expects that there is a card in the reader with an ATR that matches one of the target cards. If this bit is set, SCARD_STATE_PRESENT is assumed. This bit has no meaning to SCardGetStatusChange beyond SCARD_STATE_PRESENT.
SCARD_STATE_EXCLUSIVE
 The application expects that the card in the reader is allocated for exclusive use by another application. If this bit is set, SCARD_STATE_PRESENT is assumed.
SCARD_STATE_INUSE
 The application expects that the card in the reader is in use by one or more other applications, but may be connected to in shared mode. If this bit is set, SCARD_STATE_PRESENT is assumed.
SCARD_STATE_MUTE
 The application expects that there is an unresponsive card in the reader.
SCARD_STATE_UNPOWERED
 This implies that the card in the reader has not been powered up.

dwEventState

Current state of the reader, as known by the smart card resource manager. This field can take on any of the following values, in combination, as a bitmask.

Value Meaning
SCARD_STATE_IGNORE
 This reader should be ignored.
SCARD_STATE_CHANGED
 There is a difference between the state believed by the application, and the state known by the resource manager. When this bit is set, the application may assume a significant state change has occurred on this reader.
SCARD_STATE_UNKNOWN
 The given reader name is not recognized by the resource manager. If this bit is set, then SCARD_STATE_CHANGED and SCARD_STATE_IGNORE will also be set.
SCARD_STATE_UNAVAILABLE
 The actual state of this reader is not available. If this bit is set, then all the following bits are clear.
SCARD_STATE_EMPTY
 There is no card in the reader. If this bit is set, all the following bits will be clear.
SCARD_STATE_PRESENT
 There is a card in the reader.
SCARD_STATE_ATRMATCH
 There is a card in the reader with an ATR matching one of the target cards. If this bit is set, SCARD_STATE_PRESENT will also be set. This bit is only returned on the SCardLocateCards function.
SCARD_STATE_EXCLUSIVE
 The card in the reader is allocated for exclusive use by another application. If this bit is set, SCARD_STATE_PRESENT will also be set.
SCARD_STATE_INUSE
 The card in the reader is in use by one or more other applications, but may be connected to in shared mode. If this bit is set, SCARD_STATE_PRESENT will also be set.
SCARD_STATE_MUTE
 There is an unresponsive card in the reader.
SCARD_STATE_UNPOWERED
 This implies that the card in the reader has not been powered up.

cbAtr

Number of bytes in the returned ATR.

rgbAtr[36]

ATR of the inserted card, with extra alignment bytes.

Remarks

Note

The winscard.h header defines SCARD_READERSTATE as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header winscard.h

See also

SCardGetStatusChange

SCardLocateCards