FilterInstanceFindNext function (fltuser.h)

Article
10/13/2021

The FilterInstanceFindNext function continues a minifilter driver instance search started by a call to FilterInstanceFindFirst.

Syntax

HRESULT FilterInstanceFindNext(
  [in]  HANDLE                     hFilterInstanceFind,
  [in]  INSTANCE_INFORMATION_CLASS dwInformationClass,
  [out] LPVOID                     lpBuffer,
  [in]  DWORD                      dwBufferSize,
  [out] LPDWORD                    lpBytesReturned
);

Parameters

[in] hFilterInstanceFind

Minifilter instance search handle returned by a previous call to FilterInstanceFindFirst.

[in] dwInformationClass

The type of instance information structure returned. This parameter must contain one of the following values.

Value	Meaning
InstanceBasicInformation	Return an INSTANCE_BASIC_INFORMATION structure for the instance.
InstanceFullInformation	Return an INSTANCE_FULL_INFORMATION structure for the instance.
InstancePartialInformation	Return an INSTANCE_PARTIAL_INFORMATION structure for the instance.
InstanceAggregateStandardInformation	Return an INSTANCE_AGGREGATE_STANDARD_INFORMATION structure for the instance. The LegacyFilter portion of the structure is not utilized. This structure is available starting with Windows Vista.

[out] lpBuffer

Pointer to a caller-allocated buffer that receives the requested information. The type of the information returned in the buffer is defined by the dwInformationClass parameter.

[in] dwBufferSize

Size, in bytes, of the buffer that the lpBuffer parameter points to. The caller should set this parameter according to the given dwInformationClass.

[out] lpBytesReturned

Pointer to a caller-allocated variable that receives the number of bytes returned in the buffer that lpBuffer points to if the call to FilterInstanceFindNext succeeds. This parameter is required and cannot be NULL.

Return value

FilterInstanceFindNext returns S_OK if successful. Otherwise, it returns an HRESULT error value, such as one of the following:

Return code	Description
HRESULT_FROM_WIN32(ERROR_INSUFFICIENT_BUFFER)	The buffer pointed to by lpBuffer is not large enough to contain the requested information. When this value is returned, lpBytesReturned will contain the size, in bytes, of the buffer required for the given dwInformationClass structure.
HRESULT_FROM_WIN32(ERROR_INVALID_PARAMETER)	An invalid value was specified for the dwInformationClass parameter. For example, if InstanceAggregateStandardInformation is specified for an operating system prior to Windows Vista, FilterInstanceFindNext returns this HRESULT value.
HRESULT_FROM_WIN32(ERROR_NO_MORE_ITEMS)	This HRESULT value is returned if there are no more unique instances of the minifilter.

Remarks

After the search handle is established by calling FilterInstanceFindFirst, call FilterInstanceFindNext to search for other instances for the minifilter specified in the call to FilterInstanceFindFirst.

FilterInstanceFindNext finds one instance per call.

Requirements

Requirement	Value
Target Platform	Universal
Header	fltuser.h (include FltUser.h)
Library	FltLib.lib
DLL	FltLib.dll