SCardIntroduceReaderGroupA function (winscard.h)

Article
02/09/2023

The SCardIntroduceReaderGroup function introduces a reader group to the smart card subsystem. However, the reader group is not created until the group is specified when adding a reader to the smart card database.

Syntax

LONG SCardIntroduceReaderGroupA(
  [in] SCARDCONTEXT hContext,
  [in] LPCSTR       szGroupName
);

Parameters

[in] hContext

Supplies the handle that identifies the resource manager context. The resource manager context is set by a previous call to the SCardEstablishContext function. If this parameter is NULL, the scope of the resource manager is SCARD_SCOPE_SYSTEM.

[in] szGroupName

Supplies the display name to be assigned to the new reader group.

Value	Meaning
SCARD_ALL_READERS TEXT("SCard$AllReaders\000")	Group used when no group name is provided when listing readers. Returns a list of all readers, regardless of what group or groups the readers are in.
SCARD_DEFAULT_READERS TEXT("SCard$DefaultReaders\000")	Default group to which all readers are added when introduced into the system.
SCARD_LOCAL_READERS TEXT("SCard$LocalReaders\000")	Unused legacy value. This is an internally managed group that cannot be modified by using any reader group APIs. It is intended to be used for enumeration only.
SCARD_SYSTEM_READERS TEXT("SCard$SystemReaders\000")	Unused legacy value. This is an internally managed group that cannot be modified by using any reader group APIs. It is intended to be used for enumeration only.

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

The SCardIntroduceReaderGroup function is provided for PC/SC specification compatibility. Reader groups are not stored until a reader is added to the group.

The SCardIntroduceReaderGroup function is a database management function. For a description of other database management functions, see Smart Card Database Management Functions.

To remove a reader group, use SCardForgetReaderGroup.

Examples

The following example shows introducing a smart card reader group.

// Introduce the reader group.
// lReturn is of type LONG.
// hContext was set by a previous call to SCardEstablishContext.
lReturn = SCardIntroduceReaderGroup(hContext, 
                                    L"MyReaderGroup");
if ( SCARD_S_SUCCESS != lReturn )
    printf("Failed SCardIntroduceReaderGroup\n");

Note

The winscard.h header defines SCardIntroduceReaderGroup as an alias that 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 is 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]
Target Platform	Windows
Header	winscard.h
Library	Winscard.lib
DLL	Winscard.dll

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