SCardRemoveReaderFromGroupA function (winscard.h)

Article
02/22/2024

The SCardRemoveReaderFromGroup function removes a reader from an existing reader group. This function has no effect on the reader.

Syntax

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

Parameters

[in] hContext

Handle that identifies the resource manager context. The resource manager context is set by a previous call to SCardEstablishContext. This parameter cannot be NULL.

[in] szReaderName

Display name of the reader to be removed.

[in] szGroupName

Display name of the group from which the reader should be removed.

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

When the last reader is removed from a group, the group is automatically forgotten.

The SCardRemoveReaderFromGroup function is a database management function. For information about other database management functions, see Smart Card Database Management Functions.

To add a reader to a reader group, use SCardAddReaderToGroup.

Examples

The following example shows how to remove a reader from the group.

// Remove a reader from the group.
// lReturn is of type LONG.
// hContext was set by a previous call to SCardEstablishContext.
// The group is automatically forgotten if no readers remain in it.
lReturn = SCardRemoveReaderFromGroup(hContext, 
                                     L"MyReader",
                                     L"MyReaderGroup");
if ( SCARD_S_SUCCESS != lReturn )
    printf("Failed SCardRemoveReaderFromGroup\n");

Note

The winscard.h header defines SCardRemoveReaderFromGroup 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]
Target Platform	Windows
Header	winscard.h
Library	Winscard.lib
DLL	Winscard.dll

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